Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Protection Motivation Theory
Protection motivation theory (PMT) was originally created to help understand individual human responses to fear appeals. Protection motivation theory proposes that people protect themselves based on two factors: threat appraisal and coping appraisal. Threat appraisal assesses the severity of the situation and examines how serious the situation is, while coping appraisal is how one responds to the situation. Threat appraisal consists of the perceived severity of a threatening event and the perceived probability of the occurrence, or vulnerability. Coping appraisal consists of perceived response efficacy, or an individual's expectation that carrying out the recommended action will remove the threat, and perceived self efficacy, or the belief in one's ability to execute the recommended courses of action successfully. PMT is one model that explains why people engage in unhealthy practices and offers suggestions for changing those behaviors. It is educational and motivational. Primary prevention: taking measures to combat the risk of developing a health problem. (e.g., controlling weight to prevent high blood pressure). Secondary prevention: taking steps to prevent a condition from becoming worse. (e.g., remembering to take daily medication to control blood pressure). Another psychological model that describes self-preservation and processing of fear is terror management theory.
  • 7.7K
  • 09 Oct 2022
Topic Review
Lignosulfonates
Lignosulfonates are biobased surfactants and specialty chemicals, which are usually produced as a byproduct during sulfite pulping of wood. They are the technical lignin that is, by far, the most commercially traded and are hence vital for replacing non‑renewable and fossil‑based chemicals. Due to their prominent use as plasticizers, dispersants, and stabilizers, the physicochemical properties of lignosulfonates play a key role in determining their end‑use and performance. Their chemical composition and structure are inherently linked to the characteristic behavior of lignosulfonates. This entry hence outlines the fundamental chemistry of lignosulfonates, while discussing the following physicochemical properties: · Solubility in different solvents · Conformation and shape in aqueous solution · Self-association and agglomeration in aqueous solution · Precipitation · Adsorption at surfaces and interfaces
  • 7.7K
  • 05 Jan 2021
Topic Review
The Evolution of Computers
This research explores the evolution of computing from the earliest mechanical devices to the latest cutting-edge technologies. It covers the development of electronic computers in the 1940s and their impact on military, scientific, and business operations. Mainframe computers of the 1950s and 1960s are discussed, including their role in business computing and financial innovation. The personal computer revolution of the 1970s and the rise of mobile computing in the 1980s and 2000s are also examined. The research concludes with a look at the latest developments in computing, including quantum computing and artificial intelligence, and the potential impact of these technologies on society. It emphasizes the importance of working together to address the challenges of emerging technologies and ensuring their ethical and equitable use.
  • 7.7K
  • 22 May 2023
Topic Review
Vitamin B6 and Diabetes
Vitamin B6 is an essential nutrient for the human health. It is involved in more that 150 metabolic reactions which regulate the metabolism of glucose, lipids, amino acids, DNA, and neurotransmitters. In addition, vitamin B6 is an antioxidant molecule able to  counteracting the formation of reactive oxygen species (ROS) and advanced glycation end-products (AGEs). Epidemiological and experimental studies indicated the reduced levels of vitamin B6 can cause diabetes. In contrast other studies show that diabetes decreases vitamin B6 levels. Thus these findings lead to envisage the existence of a vicious circle at the basis of the relationship between vitamin B6 and diabetes. This entry reports the main evidence concerning the role of vitamin B6 in diabetes and examine the underlying molecular and cellular mechanisms.  
  • 7.7K
  • 28 Oct 2020
Topic Review
Free-Space Optical Communication
Fast communication is of high importance. Recently, increased data demand and crowded radio frequency spectrum have become crucial issues. Free-Space Optical Communication (FSOC) has diametrically changed the way people exchange information. As an alternative to wire communication systems, it allows efficient voice, video, and data transmission using a medium like air. Due to its large bandwidth, FSOC can be used in various applications and has therefore become an important part of our everyday life. The main advantages of FSOC are a high speed, cost savings, compact structures, low power, energy efficiency, a maximal transfer capacity, and applicability. The rapid development of the high-speed connection technology allows one to reduce the repair downtime and gives the ability to quickly establish a backup network in an emergency. Unfortunately, FSOC is susceptible to disruption due to atmospheric conditions or direct sunlight. Here, we briefly discuss Free-Space Optical Communication from mirrors and optical telegraphs to modern wireless systems and outline the future development directions of optical communication.
  • 7.7K
  • 11 Nov 2020
Topic Review
Types of Adsorbents
There are two types of adsorbents, namely, natural and synthetic adsorbents. Several examples of natural adsorbents include clay and zeolite (abundant and cheap). On the other hand, researchers can produce synthetic adsorbents (activated carbon) via agricultural waste, industrial waste, and household waste.
  • 7.7K
  • 27 Oct 2022
Topic Review
Microalgae Cell Disruption Methods
Microalgae are unicellular or simple multicellular photosynthetic microorganisms, which can normally be found in aquatic environments such as freshwater, seawater, or hypersaline lakes. These organisms can be eukaryotic or prokaryotic, the latter being the cyanobacteria, which are commonly referred to as microalgae.  The nature of the cell wall of a given microalgae species can vary, making it easier or harder to access its valuable contents. The rigidity of the cell wall can be provided, for example, by high levels of polysaccharides in the cell wall structure, such as glucose and mannose, present in Chlorella zofingiensis, or by complex sugars composition such as arabinose, galactose, rhamnose, mannose and xylose, as found in Tetraselmis suecia and T. striata. Algaenan or sporopollein is another extremely resistant biopolymer, a non-hydrolyzable biopolymer, composed of long ω-hydroxy fatty acids chains linked by several types of chemical bond, which confer its rigid properties, and that can be found in some species such as Chlorella spp., Nannochloropsis galditana and Scenedesmus spp. Arthorspira spp. cell wals contain peptidoglycan, being less rigid and, consequently, more susceptible to degradation. Thus, several methods can be applied to breakdown such molecules that, being part of the cell wall, present different level of rigidity and confer them protection against environment factors. The cell wall disruption methods include physical, chemical, enzymatic approaches. In this entry, it will be presented a brief description of these methods.
  • 7.7K
  • 29 Jan 2021
Topic Review
Fungal Metabolism
Fungi metabolism consists on a series of reactions that results in the biosynthesis of a huge number of compounds. These compounds area usually divided into primary and secondary metabolites. Primary metabolism is common to several species and usually produces compounds with the function of assuring fungi growth and development. Secondary metabolism refers to the production of compounds that are not indispensable during fungi development. Secondary metabolites are commonly referred as "natural products"  and have been extensively utilized in the pharmaceutical, cosmetics and food industry. Fungal metabolism is an excellent source of compounds related to the improvement of human health, and a discussion on this application is presented below.
  • 7.7K
  • 18 Nov 2021
Topic Review
Protein dynamics
Protein dynamics is a highly complex phenomenon comprising numerous contributions from motions with different mechanisms of action and happening with diverse timescales and amplitudes that highly depend on the system and the local environment.
  • 7.7K
  • 01 Nov 2020
Topic Review
Thermal Stability of Structural Materials
Thermal stability determines the material ability of retaining its properties at required temperatures over extended service time. In addition to temperature and time, thermal stability is affected by load conditions and environmental conditions.
  • 7.6K
  • 20 Aug 2020
  • Page
  • of
  • 5353
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Video Production Service
Feedback