Gamma secretaseGamma secretase is a multi-subunit protease complex, itself an integral membrane protein, that cleaves single-pass transmembrane proteins at residues within the transmembrane domain. Proteases of this type are known as intramembrane proteases. The most well-known substrate of gamma secretase is amyloid precursor protein, a large integral membrane protein that, when cleaved by both gamma and beta secretase, produces a short 37-43 amino acid peptide called amyloid beta whose abnormally folded fibrillar form is the primary component of amyloid plaques found in the brains of Alzheimer's disease patients.
ThioflavinThioflavins are fluorescent dyes that are available as at least two compounds, namely Thioflavin T and Thioflavin S. Both are used for histology staining and biophysical studies of protein aggregation. In particular, these dyes have been used since 1989 to investigate amyloid formation. They are also used in biophysical studies of the electrophysiology of bacteria. Thioflavins are corrosive, irritants, and are acutely toxic, causing serious eye damage. Thioflavin T has been used in research into Alzheimer's disease and other neurodegenerative diseases.
Population ageingPopulation ageing is an increasing median age in a population because of declining fertility rates and rising life expectancy. Most countries have rising life expectancy and an ageing population, trends that emerged first in developed countries but are now seen in virtually all developing countries. That is the case for every country in the world except the 18 countries designated as "demographic outliers" by the United Nations. The aged population is currently at its highest level in human history.
Surface plasmon polaritonSurface plasmon polaritons (SPPs) are electromagnetic waves that travel along a metal–dielectric or metal–air interface, practically in the infrared or visible-frequency. The term "surface plasmon polariton" explains that the wave involves both charge motion in the metal ("surface plasmon") and electromagnetic waves in the air or dielectric ("polariton"). They are a type of surface wave, guided along the interface in much the same way that light can be guided by an optical fiber.
Aging of JapanJapan has the highest proportion of elderly citizens of any country in the world. 2014 estimates showed that about 38% of the Japanese population was above the age of 60, and 25.9% was above the age of 65, a figure that increased to 29.1% by 2022. By 2050, an estimated one-third of the population in Japan is expected be 65 and older. The aging of Japanese society, characterized by sub-replacement fertility rates and high life expectancy, is expected to continue.
Population pyramidA population pyramid (age structure diagram) or "age-sex pyramid" is a graphical illustration of the distribution of a population (typically that of a country or region of the world) by age groups and sex; it typically takes the shape of a pyramid when the population is growing. Males are usually shown on the left and females on the right, and they may be measured in absolute numbers or as a percentage of the total population. The pyramid can be used to visualize the age of a particular population.
PlasmonIn physics, a plasmon is a quantum of plasma oscillation. Just as light (an optical oscillation) consists of photons, the plasma oscillation consists of plasmons. The plasmon can be considered as a quasiparticle since it arises from the quantization of plasma oscillations, just like phonons are quantizations of mechanical vibrations. Thus, plasmons are collective (a discrete number) oscillations of the free electron gas density. For example, at optical frequencies, plasmons can couple with a photon to create another quasiparticle called a plasmon polariton.
Population declinePopulation decline, also known as depopulation, is a reduction in a human population size. Over the long term, stretching from prehistory to the present, Earth's total human population has continued to grow; however, current projections suggest that this long-term trend of steady population growth may be coming to an end. Until the beginning of the Industrial Revolution, the global population grew very slowly, at about 0.04% per year. After about 1800, the growth rate accelerated to a peak of 2.
Diagnostic and Statistical Manual of Mental DisordersThe Diagnostic and Statistical Manual of Mental Disorders (DSM; latest edition: DSM-5-TR, published in March 2022) is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common language and standard criteria. It is the main book for the diagnosis and treatment of mental disorders in the United States and is considered one of the principal guides of psychiatry, along with the ICD, CCMD, and the Psychodynamic Diagnostic Manual.
Zero population growthZero population growth, sometimes abbreviated ZPG, is a condition of demographic balance where the number of people in a specified population neither grows nor declines; that is, the number of births plus in-migrants equals the number of deaths plus out-migrants. ZPG has been a prominent political movement since the 1960s. As part of the concept of optimum population, the movement considers zero population growth to be an objective towards which countries and the whole world should strive in the interests of accomplishing long-term optimal standards and conditions of living.
