Factors influencing biological behavior

The soil is a dynamic biotic and abiotic system. Pesticides deposited in or on the soil have varying capacities to be adsorbed to clay minerals and organic matter. Such adsorption reduces both the movement and the biological activity of the pesticide. In addition to soil adsorption, several other factors are known to influence the behavior and fate of pesticides after the chemicals are in contact with soil. 

Numerous biotic factors influence N processing within sediments, including the composition of the microbial, macrofaunal, and macrophyte communities, behaviors of the various infaunal communities, and trophic transfer of carbon and nitrogen between communities. Interactions between benthic communities may be physical, chemical, or biological in nature and, in turn, are influenced by the physical nature of the environment, sediment composition, and autotrophic dominance (Fig. 19.3). 

Apart from the presence of proteins, several other factors can influence NM behavior in culture media, including the salt composition, the pH, or the buffer capacity. Using gold nanoparticles (AuNP) of three sizes Maiorano et al. [24] demonstrated that the nanoparticle-protein interactions are differendy mediated when AuNP are suspended in two common cell culture media (DMEM and RPMI) supplemented with fetal bovine serum. An increased protein coating and different size distribution were observed in AuNP suspended in DMEM in comparison to RPMI. Most impor-tantiy, differences were also found in the biological responses of two cell lines (HeLa and U937), as the intracellular internalization and cytotoxicity were higher in cells exposed to AuNP in RPMI, where the protein corona was less abundant. 

In many practical applications, e.g., in the food industry or in the creation of biocompatible implants, it is very important to know the adsorption behavior of multicomponent protein mixtures. Adsorption from mixtures usually proceeds as a competitive process, and all the above-mentioned factors influence relative preference in adsorption of various proteins. In general, it was found that certain proteins may be enriched at the interface, relative to the others [8,59-61 J. Mixtures containing two or three proteins have been used as simple models of complex biological fluids, like plasma [59,60,133] or milk... 

Sociocultural, illness, and biological factors affect individual attitudes towards psychotropic medications. Health beliefs or explanatory models, particularly causal attributions regarding the illness and the treatment options afforded within such models, exert a profound influence on patients attitudes and behavior regarding medications (Smith, Lin Mendoza, 1993). Such effects can be subtle and can occur during the course of treatment even if there has been initial successful negotiation about the nature of the illness and treatment. In psychiatric illness little research has been leveled at the personal meaning that patients bring to treatment practices such as electro-convulsive therapy (ECT), oral medications, and depot injections, or to the transition between different administrative routes and types of medications. 

In addition to biological and environmental factors that influence the onset and course of drug-related problems, there also are many individual risk factors. These variables can include those related to a person s actions or behavior, those related to the way a person thinks, or those related to the experience of emotions. The next few sections will discuss in detail these personal variables that can be related to drug problems in some people. 

Humans differ in sensitivity due to biological factors such as metabolic polymorphism, age, gender, health status, and nutritional status. These differences can be the result of genetic and/or environ-mental/behavioral influences. This intraspecies (interindividual) variation is greater in humans than in the more inbred experimental animal population. 

This article discusses some micellar and liquid crystalline phases with nonionic substances, water, and hydrocarbons and some factors are delineated for their association phenomena. Lipid phase behavior has an extremely important direct influence on certain biological phenomena (Chapter 10) and is treated in Chapter 4. The treatment here is limited... 

Many biological factors such as age and weight play a crucial role in the way that drugs affect the brain and influence behavior. So, too, does the unique neural circuitry that you inherited from your parents and that sometimes influences whether a drug will be exciting or depressing to you. This concept was probably... 

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