1. Plants can experience either chilling stress from temperatures between 0-15°C or freezing stress from temperatures below 0°C. Chilling can disrupt metabolic processes while freezing can cause either vitrification or ice crystal formation within plant tissues and cells.
2. Cold hardening allows plants to acclimate to cold temperatures by modifying membrane lipids and lowering optimal temperatures for photosynthesis. Other protections include soil banking, wrapping tree trunks, sprinkling, fogging, and using wind machines or warm water circulation.
3. Symptoms of freezing injury include foliage desiccation, water-soaked areas developing into necrotic spots, and apparent wilting from damaged roots or conductive tissues. Cold stress response is complex and involves
Water Stress in Plant: Causes, Effects and ResponsesSukhveerSingh31
Drought, as an abiotic stress, is multidimensional in nature, and it affects plants at various levels of their organization.Drought stress effects can be managed by production of most appropriate plant genotypes, seed priming, plant growth regulators, use of osmoprotectants, silicon and some other strategies.
Drought stress effects can be managed by production of most appropriate plant genotypes, seed priming, plant growth regulators, use of osmoprotectants, silicon and some other strategies.
Outline
Introduction (Salinity)
State wise salt affected areas and distribution
Causes of soil salinity
Classification of plants based on salt tolerance
Salinity stress effect on crop growth and development
Salinity stress tolerance
Mechanism of salt tolerance
Mitigation of salt stress
Case study
Salinity is one of the most important factors, limiting the productivity of agricultural crops, with adverse effects on germination, plant vigour and crop yield (R Munns & Tester, 2008)
It is caused due to high accumulation of SO 4 2- , NO 3- , CO3- of Calcium, Magnesium and Sodium.
Excess salt in the soil, reduces the water potential of the soil and making the soil solution unavailable to the plants (physiological drought)
Salinity stress
Categorization of salt affected soils
CAUSES OF SALINITY IN SOIL
Salinity effects on Plants
Injuries due to salt stress
different strategies to avoid salt injury
salt tolerance
salt avoidance
salt evasion
halophytes
non halophytes
glycophytes
Breeding for salt tolerance
Heavy metal stress
EFFECTS OF HEAVY METAL ON PLANTS
Sources of metal toxicity
Chromium, manganese, zinc, aluminum, copper, nickel
ALLUMINIUM TOXICITY IN SOIL
Inhibition of Ca Uptake by AIuminium
Aluminium tolerance in soil by internal accumulation
Aluminium tolerance in soil by exclusion
CADMIUM TOXICITY IN SOIL
CADMIUM ACCUMULATION IN PLANTS
CADMIUM TOXICITY IN PLANTS
CADMIUM TOLERANCE MECHANISM
ROLE OF PHYTOCHELATINS
Ecophysiological Effects of Changing Atmospheric Carbon Dioxide ConcentrationAsad Afridi
this presentation is about Carbon Dioxide. different effects of carbon dioxide are discussed in this presentation. such as effects on different plants, animals and environment.
Being sessile, plants are constantly exposed to changes in temperature and other abiotic stress factors. The temperature stress experienced by plants can be classified into three types: those occurring at (a) temperature below freezing (b) low temperature above freezing and (c) high temperature. The plants must adapt to them in other ways. The biological substances that are deeply related to these stresses, such as heat shock proteins, glycine betaine as a compatible solute, membrane lipids etc.and also detoxifiers of active oxygen species, contribute to temperature stress tolerance in plants. Rapid advances in Molecular Genetic approaches have enabled genes to be cloned, both from prokaryotes and directly from plants themselves, that are thought to provide the key to the mechanism of temperature adaptation (Iba et al., 2002).
The accumulation of heat shock proteins under the control of heat stress transcription factors is assumed to play a central role in the heat stress response and in acquired thermotolerance in plants (Kotak et al., 2007). The pattern of protein synthesis during cold acclimation is very dissimilar to the heat shock proteins in many ways. Different low temperature stress proteins, such as Anti-freeze proteins or thermal hysteresis proteins (THPs) and cold shock domain proteins etc. are accumulated in plant cell and are frequently correlated with enhanced cold tolerance ( Guy, 1999).
The heat stress-induced dehydrin proteins (DHNs) expression and their relationship with the water relations of sugarcane (Saccharum officinarum L.) leaves were studied to investigate the adaptation to heat stress in plants (Wahid and Close, 2007). In order to get an in vitro evidence of Hsc70 functioning as a molecular chaperone during cold stress, a cold-inducible spinach cytosolic Hsc70 was subcloned into a protein expression vector and the recombinant protein was expressed in bacterial cells. Results suggest that the molecular chaperone Hsc70 may have a functional role in plants during low temperature stress (Zhang and Guy, 2006). To analyze the least and most strongly interacting stress with Hsps and Hsfs, a transcriptional profiling of Arabidopsis Hsps and Hsfs has been done (Swindell et al., 2007).
As plants receive complex of stress factors together, therefore in future research, emphasis should be placed on such cases where tolerance is attempted to different stress factors simultaneously by employing sophisticated techniques.
Cellular signal transduction pathways under abiotic stressSenthil Natesan
Abiotic stresses, especially cold, salinity and drought, are the primary causes of crop loss worldwide. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Plants have stress-specific adaptive responses as well as responses which protect the plants from more than one environmental stress. There are multiple stress perception and signaling pathways, some of which are specific, but others may cross-talk at various steps (Knight & knight ,2001).Many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway (Miura and Furumoto,2013 ) . The Salt-Overly-Sensitive (SOS) pathway, identified through isolation and study of the sos1, sos2, and sos3 mutants, is essential for maintaining favorable ion ratios in the cytoplasm and for tolerance of salt stress (shi .et al ,2002). Both ABA-dependent and -independent signaling pathways appear to be involved in osmotic stress tolerance (Nakashima and shinozaki, 2013) .ROS play a dual role in the response of plants to abiotic stresses functioning as toxic by-products of stress metabolism, as well as important signal transduction molecules and the ROS signaling networks can control growth, development, and stress response ( Mahajan,s and Tuteja, 2005) .
Water Stress in Plant: Causes, Effects and ResponsesSukhveerSingh31
Drought, as an abiotic stress, is multidimensional in nature, and it affects plants at various levels of their organization.Drought stress effects can be managed by production of most appropriate plant genotypes, seed priming, plant growth regulators, use of osmoprotectants, silicon and some other strategies.
Drought stress effects can be managed by production of most appropriate plant genotypes, seed priming, plant growth regulators, use of osmoprotectants, silicon and some other strategies.
Outline
Introduction (Salinity)
State wise salt affected areas and distribution
Causes of soil salinity
Classification of plants based on salt tolerance
Salinity stress effect on crop growth and development
Salinity stress tolerance
Mechanism of salt tolerance
Mitigation of salt stress
Case study
Salinity is one of the most important factors, limiting the productivity of agricultural crops, with adverse effects on germination, plant vigour and crop yield (R Munns & Tester, 2008)
It is caused due to high accumulation of SO 4 2- , NO 3- , CO3- of Calcium, Magnesium and Sodium.
Excess salt in the soil, reduces the water potential of the soil and making the soil solution unavailable to the plants (physiological drought)
Salinity stress
Categorization of salt affected soils
CAUSES OF SALINITY IN SOIL
Salinity effects on Plants
Injuries due to salt stress
different strategies to avoid salt injury
salt tolerance
salt avoidance
salt evasion
halophytes
non halophytes
glycophytes
Breeding for salt tolerance
Heavy metal stress
EFFECTS OF HEAVY METAL ON PLANTS
Sources of metal toxicity
Chromium, manganese, zinc, aluminum, copper, nickel
ALLUMINIUM TOXICITY IN SOIL
Inhibition of Ca Uptake by AIuminium
Aluminium tolerance in soil by internal accumulation
Aluminium tolerance in soil by exclusion
CADMIUM TOXICITY IN SOIL
CADMIUM ACCUMULATION IN PLANTS
CADMIUM TOXICITY IN PLANTS
CADMIUM TOLERANCE MECHANISM
ROLE OF PHYTOCHELATINS
Ecophysiological Effects of Changing Atmospheric Carbon Dioxide ConcentrationAsad Afridi
this presentation is about Carbon Dioxide. different effects of carbon dioxide are discussed in this presentation. such as effects on different plants, animals and environment.
Being sessile, plants are constantly exposed to changes in temperature and other abiotic stress factors. The temperature stress experienced by plants can be classified into three types: those occurring at (a) temperature below freezing (b) low temperature above freezing and (c) high temperature. The plants must adapt to them in other ways. The biological substances that are deeply related to these stresses, such as heat shock proteins, glycine betaine as a compatible solute, membrane lipids etc.and also detoxifiers of active oxygen species, contribute to temperature stress tolerance in plants. Rapid advances in Molecular Genetic approaches have enabled genes to be cloned, both from prokaryotes and directly from plants themselves, that are thought to provide the key to the mechanism of temperature adaptation (Iba et al., 2002).
The accumulation of heat shock proteins under the control of heat stress transcription factors is assumed to play a central role in the heat stress response and in acquired thermotolerance in plants (Kotak et al., 2007). The pattern of protein synthesis during cold acclimation is very dissimilar to the heat shock proteins in many ways. Different low temperature stress proteins, such as Anti-freeze proteins or thermal hysteresis proteins (THPs) and cold shock domain proteins etc. are accumulated in plant cell and are frequently correlated with enhanced cold tolerance ( Guy, 1999).
The heat stress-induced dehydrin proteins (DHNs) expression and their relationship with the water relations of sugarcane (Saccharum officinarum L.) leaves were studied to investigate the adaptation to heat stress in plants (Wahid and Close, 2007). In order to get an in vitro evidence of Hsc70 functioning as a molecular chaperone during cold stress, a cold-inducible spinach cytosolic Hsc70 was subcloned into a protein expression vector and the recombinant protein was expressed in bacterial cells. Results suggest that the molecular chaperone Hsc70 may have a functional role in plants during low temperature stress (Zhang and Guy, 2006). To analyze the least and most strongly interacting stress with Hsps and Hsfs, a transcriptional profiling of Arabidopsis Hsps and Hsfs has been done (Swindell et al., 2007).
As plants receive complex of stress factors together, therefore in future research, emphasis should be placed on such cases where tolerance is attempted to different stress factors simultaneously by employing sophisticated techniques.
Cellular signal transduction pathways under abiotic stressSenthil Natesan
Abiotic stresses, especially cold, salinity and drought, are the primary causes of crop loss worldwide. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Plants have stress-specific adaptive responses as well as responses which protect the plants from more than one environmental stress. There are multiple stress perception and signaling pathways, some of which are specific, but others may cross-talk at various steps (Knight & knight ,2001).Many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway (Miura and Furumoto,2013 ) . The Salt-Overly-Sensitive (SOS) pathway, identified through isolation and study of the sos1, sos2, and sos3 mutants, is essential for maintaining favorable ion ratios in the cytoplasm and for tolerance of salt stress (shi .et al ,2002). Both ABA-dependent and -independent signaling pathways appear to be involved in osmotic stress tolerance (Nakashima and shinozaki, 2013) .ROS play a dual role in the response of plants to abiotic stresses functioning as toxic by-products of stress metabolism, as well as important signal transduction molecules and the ROS signaling networks can control growth, development, and stress response ( Mahajan,s and Tuteja, 2005) .
Freezing has been successfully employed for the long-term preservation of many foods, providing a significantly extended shelf life.
The process involves lowering the product temperature generally to -18 °C or below.The extreme cold simply retards the growth of microorganisms and slows
down the chemical changes that affect quality or cause food to spoil.
During freezing the cellular solution present in the food matrix is cooled to its initial freezing point, and further cooling causes the water molecule to
separate, forming ice crystal.
The migration of water molecules during crystallization led to an increase in osmotic pressure, further enhancing the water permeability of the cell membranes. This transport of water molecules, if not controlled, can eventually affect the microstructure of the frozen produce.
The freezing process occurs in two successive steps, i.e,
” NUCLEATION” and “CRYSTAL GROWTH”.
Physical and chemical process within the plants are goverened by temperature
The diffusion rate of gases and liquids
Solubility of different substances
Rate of reactions
Stability of the enzyme system
Normally the growth permitting range of temperature – 10℃- 45 ℃ - Biokinetic zone
There are some areas of the world in which the agricultural crops require assistance and cooling, especially
during hot days, in order
to prevent them from being subjected to unnecessary stress. In other areas, the color of fruit can be improved by cooling the trees
during the correct time period.
It is possible to extend the shelf life of some types of fruit by cooling them while they are still on the trees. And by using correct and
supervised cooling, we can increase the flower fruit set during periods of very hot weather. In other regions, we can aid and improve
the yield of fruit crops by cooling during the autumn and winter months, and then adding cold units to the same trees or cooling the
same crops at the end of the winter months in order to cause early blossoming.
In addition to employing cooling in open fields, an additional—perhaps primary—use of cooling is in various
types of greenhouses.
The principle of a greenhouse
is that the farmer can control its internal climate and thereby provide the plants with optimal growth
conditions. Therefore, a system that will have a cooling
effect on the internal temperature on hot days is almost indispensable for
every greenhouse.
Another use of a cooling system inside a greenhouse
is, perhaps surprisingly, in cold countries where the greenhouse is especially
built with few ventilation
openings to conserve internal heat. As a result of this design, on the few days that are very hot, there is
insufficient air flow to cool the interior. An efficient cooling system can solve the problem. Further, in these same cold countries, the
crops are usually
already inside the greenhouse by the first days of spring, but the heating system still needs to be operated
in order
to ensure the correct conditions. The windows must not be opened, and inside the building,
the relative humidity drops beneath the
desired levels. At this time, operating a suitable cooling system improves these crops.
What is possible to do to improve agricultural crops is also possible to do with livestock, including all types of poultry, cows, and pigs.
A suitable system can cool their micro-environment and improve production.
The different methods of cooling based on sprinkler-spraying products are as follows
Dehydration
food dehydration
preservation effect
controlling factors for dehydration
factors affecting dehydration
driers commonly used are
dehydration and nutritive value
disadvantage
drying and microbes
Post-harvest management of Ilium is discussed. It deals with the following,
# Harvesting stage
# How to extend the vase life of a cut flower
# How to overcome the post-harvest diseases.
# Mode of harvesting
# Importance
# How to improve vase life
# Causes of bud blast
# Leaf yellowing
# Effect of cold storage
# Temperature variation
Season Extension for Gardening; Gardening Guidebook for Chatham County, North Carolina ~ Central Carolina Community College ~ For more information, Please see websites below:
`
Organic Edible Schoolyards & Gardening with Children =
http://scribd.com/doc/239851214 ~
`
Double Food Production from your School Garden with Organic Tech =
http://scribd.com/doc/239851079 ~
`
Free School Gardening Art Posters =
http://scribd.com/doc/239851159 ~
`
Increase Food Production with Companion Planting in your School Garden =
http://scribd.com/doc/239851159 ~
`
Healthy Foods Dramatically Improves Student Academic Success =
http://scribd.com/doc/239851348 ~
`
City Chickens for your Organic School Garden =
http://scribd.com/doc/239850440 ~
`
Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica
http://scribd.com/doc/239850233
`
Simple Square Foot Gardening for Schools - Teacher Guide =
http://scribd.com/doc/239851110
Abiotic stress factors or stressors are naturally occurring, often intangible factors
The four major abiotic stresses: drought , salinity, temperature and heavy metals, cause drastic yield reduction in most crops.
Few of the types of abiotic stresses are:
1)Water-logging & drought
2)Excessive soil salinity
3)High or low temperatures
4)Ozone
5)Low oxygen
6)Phytotoxic compounds
8)Inadequate mineral in the soil
9)Too much or too little light
This presentation focuses on the adaptations in plants against abiotic stress and the ways that how they tolerate it with different mechanisms.
- Haider Ali Malik
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.
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.
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.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
2. CONTENTS
• Abstract
• Cold temperature .determent
• Damage of cold
• Chilling injury musa
• Symptoms of Freezing injury
• Introduction
• Chilling Affects on plants
• Causes of Chilling injury
• Freezing injury Two types of
freezing occur in plant cells and
tissues
• Preventions & Protection by
A . Cold hardening B . SOIL BANKING
C . Wrapping D . Sprinkling
E . Fogging F . Air movement
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3. ABSTRACT
• Plants are constantly exposed to a variety of environmental stresses.
Freezing or extremely low temperature constitutes a key factor
influencing plant growth, development and crop productivity. Plants
have evolved a mechanism to enhance tolerance to freezing during
exposure to periods of low, but non-freezing temperatures. This
phenomenon is called cold acclimation. During cold acclimation, plants
develop several mechanisms to minimize potential damages caused by
low temperature. Cold response is highly complex process that involves
an array of physiological and biochemical modifications.
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4. INTRODUCTION
• Only one-third of the total land area on Earth is free of ice and 42% of land
experiences temperatures below −20 °C. In such areas, plants require
specialized mechanisms to survive exposure to low temperature. Cold stress
can be classified as chilling (0–15 °C) and freezing (<0 °C) stresses. Generally,
plants originating from temperate regions, such as spinach and Arabidopsis,
exhibit a variable degree of chilling tolerance and can increase their freezing
tolerance during exposure to chilling and non-freezing temperatures. This
process is known as cold acclimation . On the other hand, plants of tropical
and subtropical origins are sensitive to chilling stress and lack the cold
acclimation mechanism.
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5. 1. Chilling ; it is ( T > 0 C ) Plant chilling injury refers to an
injury that is caused by a temperature drop to below 15°C
but above the freezing point.
2. Freezing ; it is (T < 0 C ) Freezing injury in plants can be
from two sources:
A. Freezing of soil water, and;
B. Freezing of the fluids within the plant.
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6. CHILLING AFFECTS ON PLANTS
• injury causes several metabolic of physiological dysfunctions to
the plant including •
• disruption of the conversion of starch to sugars (amylotytic
activity) •
• decreased carbon dioxide exchange •
• reduction in net photosynthesis •
• the destruction/degradation of chlorophyll
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7. DAMAGE OF COLD
Depends of many factors .
1. Development stage
2. Duration / severity of frost
3. Rates of cooling
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8. CAUSES OF CHILLING INJURY
• The primary cause has been found to be the opening (and locking)
of the leaf stomata when the permeability of the roots to water is
low •
• The leaves lose water faster than it can be replaced and they
become dehydrated.. •
• In some plants, the stomata behave properly at chilling
temperatures and the injury is said to be metabolic •
• A decrease in respiration, photosynthesis and fatty acid synthesis
may all contribute to the chill-starvation of some plants.
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10. FREEZING INJURY TWO TYPES OF
FREEZING OCCUR IN PLANT CELLS AND
TISSUES
• vitrification : Solidification of the cellular content into noncrystalline
state. It occurs by rapid freezing of cells to a very low temperature .
• Crystallization / ice formation : Crystallization of ice occur either
extracellularly or intracellularly
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12. SYMPTOMS OF FREEZING INJURY
• Desiccation or burning of foliage
• Water-soaked areas that progress to necrotic spots on leaves, stems or fruit and
death of sections of the plant or the entire plant.
• Close examination of woody plants several days or weeks after freezing may
reveal a dead or weakened root system or split bark on stems or branches.
• Obvious symptoms on plant foliage may not be present until after the plant has
been stressed by warm temperatures.
• A hot, bright day could increase transpirational water loss beyond the ability of
injured roots or stem conductive tissue to replace.
• Wilting and/or desiccation, as caused by direct drought stress.
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14. PREVENTIONS & PROTECTION
1. Cold hardening
Cold hardening alters the behavior of the stomata so
that they close under the same conditions; the root
permeability is also increased.
Cold hardening affects the lipid content of cell
membranes and has been found to lower the optimum
temperature for photosynthesis and respiration.
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16. 2. SOIL BANKING .
• It consists of placing a mound of soil around the
tree’s trunk to protect the bud union and trunk
from cold.
• One of the most efficient cold protection
methods for young trees and has been used with
success for many years
Preventions & Protection
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17. PREVENTIONS & PROTECTION
3. Wrapping
• Most tree wraps can be attached anytime
during the year and left on the tree
throughout the year or even for several
years.
• When freeze damage occurs, wraps
should be removed or pushed down to
allow for growth of new shoots.
• Wraps should be properly positioned and
fastened around the trunk for best results.
• It is important to cover the entire lower
trunk, especially at the base.
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18. PREVENTIONS & PROTECTION
4 .Sprinkling
• It can be used to moderate temperatures above freezing
because of sensible heat in water and can maintain plant leaf
temperature at 1 to 2°C degrees or more.
• Water applied to aisles of shade structures or greenhouses
increases the moisture content of the air and soil surrounding
the plants, thus slowing the rate of temperature drop.
• The water absorbs heat during the day which is released slowly
at night.
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19. PREVENTIONS & PROTECTION
5. Fogging
• Fog also retards the loss
of heat from soil and
plant surfaces to the
atmosphere
• Fog can provide up to
4°C of protection
outdoors during
radiational cooling
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20. PREVENTIONS & PROTECTION
6. Supplementary Heat supply Air movement method:
• Wind machines have been used for many years in citrus and
vegetable industries and recently in the ornamental industry as a
means of cold protection •Air movement also helps distribute and
circulate heat added by orchard heaters or other sources. Warm
water movement:
• Circulation of warm water (43 to 54°C), not hot water, in enclosed
growing and/or storage areas is effective to prevent cold injuries
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22. REFERENCES
• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3129041/
• Physiology and Molecular Biology of Stress Tolerance in Plants book
• Cold Signaling and Cold Response in Plants . (ARTICLE)
• MORPHO-PHYSIOLOGICAL TRAITS ASSOCIATED WITH COLD STRESS
TOLERANCE IN TROPICAL MAIZE (ZEA MAYS L.) (ARTICLE)
• Physiological and Metabolic Responses of Winter Wheat to Prolonged
Freezing Stress‘ (ARTICLE)
• REVIEW ARTICLE .Cold stress and acclimation
• http://www.slideshare.net/rajeshdebnath545/chilling-freezing-
injuries-of-crops
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