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Susceptibility (botany)
Susceptibility may refer to: Physics and engineering In physics the susceptibility is a quantification for the change of an extensive property under variation of an intensive property. The word may refer to: * In physics, the susceptibility of a material or substance describes its response to an applied field. For example: ** Magnetic susceptibility ** Electric susceptibility * The two types of susceptibility above are examples of a linear response function; sometimes the terms ''susceptibility'' and ''linear response function'' are used interchangeably. *In electromagnetic compatibility (EMC), susceptibility is the sensitivity of a device's function to incoming electromagnetic interference Health and medicine * In epidemiology, a susceptible individual is a member of a population who is at risk of becoming infected by a disease * In microbiology, pharmacology, and medicine drug susceptibility is the ability of a microorganism to be inhibited or killed by the drug, as in antibiot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intensive And Extensive Properties
Physical properties of materials and systems can often be categorized as being either intensive or extensive, according to how the property changes when the size (or extent) of the system changes. According to IUPAC, an intensive quantity is one whose magnitude is independent of the size of the system, whereas an extensive quantity is one whose magnitude is additive for subsystems. The terms ''intensive and extensive quantities'' were introduced into physics by German writer Georg Helm in 1898, and by American physicist and chemist Richard C. Tolman in 1917. An intensive property does not depend on the system size or the amount of material in the system. It is not necessarily homogeneously distributed in space; it can vary from place to place in a body of matter and radiation. Examples of intensive properties include temperature, ''T''; refractive index, ''n''; density, ''ρ''; and hardness, ''η''. By contrast, extensive properties such as the mass, volume and entropy of syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Susceptibility
In electromagnetism, the magnetic susceptibility (Latin: , "receptive"; denoted ) is a measure of how much a material will become magnetized in an applied magnetic field. It is the ratio of magnetization (magnetic moment per unit volume) to the applied magnetizing field intensity . This allows a simple classification, into two categories, of most materials' responses to an applied magnetic field: an alignment with the magnetic field, , called paramagnetism, or an alignment against the field, , called diamagnetism. Magnetic susceptibility indicates whether a material is attracted into or repelled out of a magnetic field. Paramagnetic materials align with the applied field and are attracted to regions of greater magnetic field. Diamagnetic materials are anti-aligned and are pushed away, toward regions of lower magnetic fields. On top of the applied field, the magnetization of the material adds its own magnetic field, causing the field lines to concentrate in paramagnetism, or be excl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Susceptibility
In electricity (electromagnetism), the electric susceptibility (\chi_; Latin: ''susceptibilis'' "receptive") is a dimensionless proportionality constant that indicates the degree of polarization of a dielectric material in response to an applied electric field. The greater the electric susceptibility, the greater the ability of a material to polarize in response to the field, and thereby reduce the total electric field inside the material(and store energy). It is in this way that the electric susceptibility influences the electric permittivity of the material and thus influences many other phenomena in that medium, from the capacitance of capacitors to the speed of light. Definition for linear dielectrics If a dielectric material is a linear dielectric, then electric susceptibility is defined as the constant of proportionality (which may be a matrix) relating an electric field E to the induced dielectric polarization density P such that \mathbf P =\varepsilon_0 \chi_, wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Response Function
A linear response function describes the input-output relationship of a signal transducer such as a radio turning electromagnetic waves into music or a neuron turning synaptic input into a response. Because of its many applications in information theory, physics and engineering there exist alternative names for specific linear response functions such as susceptibility, impulse response or impedance, see also transfer function. The concept of a Green's function or fundamental solution of an ordinary differential equation is closely related. Mathematical definition Denote the input of a system by h(t) (e.g. a force), and the response of the system by x(t) (e.g. a position). Generally, the value of x(t) will depend not only on the present value of h(t), but also on past values. Approximately x(t) is a weighted sum of the previous values of h(t'), with the weights given by the linear response function \chi(t-t'): x(t) = \int_^t dt'\, \chi(t-t') h(t') + \cdots\,. The explicit term o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Compatibility
Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to function acceptably in their electromagnetic environment, by limiting the unintentional generation, propagation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage in operational equipment. The goal of EMC is the correct operation of different equipment in a common electromagnetic environment. It is also the name given to the associated branch of electrical engineering. EMC pursues three main classes of issue. Emission is the generation of electromagnetic energy, whether deliberate or accidental, by some source and its release into the environment. EMC studies the unwanted emissions and the countermeasures which may be taken in order to reduce unwanted emissions. The second class, susceptibility, is the tendency of electrical equipment, referred to as the victim, to malfunction or break down in the presen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Susceptible Individual
In epidemiology a susceptible individual (sometimes known simply as a susceptible) is a member of a population who is at risk of becoming infected by a disease. Susceptible individuals Susceptibles have been exposed to neither the wild strain of the disease nor a vaccination against it, and thus have not developed immunity. Those individuals who have antibodies against an antigen associated with a particular infectious disease will not be susceptible, even if they did not produce the antibody themselves (for example, infants younger than six months who still have maternal antibodies passed through the placenta and from the colostrum, and adults who have had a recent injection of antibodies). However, these individuals soon return to the susceptible state as the antibodies are broken down. Some individuals may have a natural resistance to a particular infectious disease. However, except in some special cases such as malaria, these individuals make up such a small proportion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic Sensitivity
Antibiotic sensitivity testing or antibiotic susceptibility testing is the measurement of the susceptibility of bacteria to antibiotics. It is used because bacteria may have resistance to some antibiotics. Sensitivity testing results can allow a clinician to change the choice of antibiotics from empiric therapy, which is when an antibiotic is selected based on clinical suspicion about the site of an infection and common causative bacteria, to directed therapy, in which the choice of antibiotic is based on knowledge of the organism and its sensitivities. Sensitivity testing usually occurs in a medical laboratory, and uses culture methods that expose bacteria to antibiotics, or genetic methods that test to see if bacteria have genes that confer resistance. Culture methods often involve measuring the diameter of areas without bacterial growth, called zones of inhibition, around paper discs containing antibiotics on agar culture dishes that have been evenly inoculated with bacteria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Disease Resistance
Plant disease resistance protects plants from pathogens in two ways: by pre-formed structures and chemicals, and by infection-induced responses of the immune system. Relative to a susceptible plant, disease resistance is the reduction of pathogen growth on or in the plant (and hence a reduction of disease), while the term disease tolerance describes plants that exhibit little disease damage despite substantial pathogen levels. Disease outcome is determined by the three-way interaction of the pathogen, the plant and the environmental conditions (an interaction known as the disease triangle). Defense-activating compounds can move cell-to-cell and systematically through the plant's vascular system. However, plants do not have circulating immune cells, so most cell types exhibit a broad suite of antimicrobial defenses. Although obvious ''qualitative'' differences in disease resistance can be observed when multiple specimens are compared (allowing classification as “resistant” or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychological Warfare
Psychological warfare (PSYWAR), or the basic aspects of modern psychological operations (PsyOp), have been known by many other names or terms, including Military Information Support Operations (MISO), Psy Ops, political warfare, "Hearts and Minds", and propaganda. The term is used "to denote any action which is practiced mainly by psychological methods with the aim of evoking a planned psychological reaction in other people". Various techniques are used, and are aimed at influencing a target audience's value system, belief system, emotions, motives, reasoning, or behavior. It is used to induce confessions or reinforce attitudes and behaviors favorable to the originator's objectives, and are sometimes combined with black operations or false flag tactics. It is also used to destroy the morale of enemies through tactics that aim to depress troops' psychological states. Target audiences can be governments, organizations, groups, and individuals, and is not just limited to sold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
