Organisms animal-like

There is a continuing interest in the development of biomarker assays for use in environmental risk assessment. As discussed elsewhere (Section 16.6), there are both scientific and ethical reasons for seeking to introduce in vitro assays into protocols for the regulatory testing of chemicals. Animal welfare organizations would like to see the replacement of toxicity tests by more animal-friendly alternatives for all types of risk assessment—whether for environmental risks or for human health. 

The potential for 2,3-benzofuran to be bioconcentrated by aquatic organisms is likely to be moderate. A bioconcentration factor (BCE) is the ratio of the concentration of a chemical in the tissues of aquatic animals to the concentration of the chemical in the water in which they live. No experimentally measured value for the BCF of 2,3-benzofuran was located, but the octanol-water partition coefficient (K ) of 2,3-benzofuran has been measured as 468 (Leo et al. 1971). The empirical regressions of Neeley et al. (1974) relate the values of and BCF for other compounds, and can be used to estimate that the BCF of 2,3-benzofuran is approximately 40. If this estimate is correct, substantial bioconcentration of 2,3-benzofuran by aquatic organisms would not be expected. 

PROTIST A unicellular nucleate organism a primitive type or relatively primitive type, of organism always having nucleate cells it may be distinctly animal-like, distinctly plant-like, or they may have characteristics ordinarily associated with both plants and animals any member of the kingdom Protista. 

Amines, especially those with significant volatility, have unpleasant odors. Some of them smell like ammonia, others smell fishy, while others are indescribably revolting. The alkanediamines of structure H2N(CH2) NH2 are notably wretched and two are aptly called putrescine (n = 4) and cadav-erine (n = 5). As you may guess from the names, these compounds are among the amines produced by bacterial decay of organic animal matter (putrefaction of protein) and are poisonous components (ptomaines) thereof. 

Parasitic stages, on the other hand, generally do not use oxygen as the final electron acceptor but use fermentative processes to obtain most of their ATP. For these stages, an uneconomical energy metabolism is not detrimental, as the host provides the nutrients. Most adult flatworms inside the final host produce end products of a fermentative carbohydrate breakdown, such as succinate, acetate, propionate and lactate. These end products are formed via malate dismutation, a fermentative pathway, which is present in all types of parasitic worms (flatworms as well as many nematodes), but which is also present in animals like freshwater snails, mussels, oysters and other marine organisms. Malate dismutation is linked to a specially... 

Human cells, tissues, or organs implanted or transplanted in animals present a relatively strong and valuable tool, provided that immune rejection of the human material can be avoided. Immune-deficient animals like mice may well be used to develop organ-like structures (teratomas) from transplanted stem cells [13] or with combinations of human cells or human tissue (e.g., synoviocytes and cartilage [14], and activated mononuclear cells and transplanted skin [15]). 

In its simplest terms, biomass is all the plant matter found on our planet. Biomass is produced directly by photosynthesis, the fundamental engine of life on earth. Plant photosynthesis uses energy from the sun to combine carbon dioxide from the atmosphere with water to produce organic plant matter. More inclusive definitions are possible. For example, animal products and waste can be included in the definition of biomass. Animals, like plants, are renewable but animals clearly are one step removed from the direct use of sunlight. Using animal rather than plant material thus leads to substantially less efficient use of our planet s ultimate renewable resource, the sun. So, we emphasize plant matter in our definition of biomass. It is the photosynthetic capability of plants to utlize carbon dioxide from... 

Comparative Toxicokinetics. One study in rabbits fed tetryl showed that the chemical is absorbed and metabolized (Zambrano and Mandovano 1956). Picramic acid was detected in the urine of these animals. Since there were no other studies available, the toxicokinetics cannot be compared. The best animal models for studying the health effects of the chemical are not known. Further studies would be useful to determine if the target organs are likely to be the same in humans and animals. 

Capsaicin is the compound responsible for the characteristic spicy flavor of jalapeho and habahero peppers. Although it first produces a burning sensation on contact with the mouth or skin, repeated application desensitizes the area to pain. This property has made it the active ingredient in several topical creams for treatment of chronic pain. Capsaicin has also been used as an animal deterrent in pepper sprays, and as an additive to make birdseed squirrel-proof In Chapter 1, we discuss the structure, bonding, and properties of organic molecules like capsaicin. 

Another prerequisite for life is liquid water, the medium in which biochemical reactions take place and usually the main constituent of organisms. Although bacteria, and even some simple animals, like the tardigrade, can survive in a dormant state without water, the processes that we associate with life can only take place in its presence. This requirement obviously imposes temperature limits on environments that can be considered suitable for life hence one of the criteria in the search for life on other planets is evidence for the existence of liquid water at some stage of a planet s life. 

Metabolism of organic bindings as substrate. It is well known that natural organic bindings, like animal or plant glue, lose their binding effect when... 

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