Scientific background

The physical and chemical properties of lactic acid are extensively covered by Holten et aL (1971). Some of these properties are listed in Table 1.7. 

The two optically active enantiomeric forms are L(-t) dextrorotary and D(—) levorotary  

O 2flhfel.7(fromLitchfield 1996) shows that the zinc salts of the two enantiomers have the reverse optical activity of the free 

Lactobacillus rhamnosus (formerly L. delbrueckii) produces high yields of L(+)-lactic acid from sucrose and glucose at 45 °C, making it an excellent commercial production strain (O Table 1.8). But this bacterium will not utilize lactose, so it cannot make use of cheese whey. Lactobacillus delbrueckii subsp. bulgaricus and L. helveticus both ferment lactose from cheese whey, producing high yields of lactic acid. Lactobacillus delbrueckii produces the d(—) enantiomer and L. helveticus a racemic mixture of DL-lactic acid. Because most commercial fermentations are developed for L(+)-lactic add production, strains of L. casei and Lactococcus lactis are being developed for fermentation of lactose sources such as cheese whey. 

Selected lactic acid bacteria their fermentation pathways, lactic acid enantiomer produced, and major carbon sources used 

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The factor of safety had little scientific background, but had an underlying empirical and subjective nature. No one can dispute that at the time that stress analysis was in its infancy, this was the best knowledge available, but they are still being applied today Factors of safety that are recommended in recent literature range from 1.25 to 10 for various material types and loading conditions (Edwards and McKee, 1991 Haugen, 1980). 

Contents The telescope and imagination—The "new astronomy" and English imagination.— Kepler, the Somnium, and John Donne.—Milton and the telescope —The scientific background of Swift s Voyage to Laputa, with N. M. Mohler.—The microscope and English imagination... 

Hauschild M, Wenzel H (eds) (1998) Environmental assessment of products Volume 2 Scientific background. Chapman Hall, London... 

There is a strong need to train of new professionals in commercial or governmental initiatives, and teach them mastery the scientific background of biological decontamination and specific features of in-field applications. As the most relevant pollution problems are localised in the less developed countries, training per se may not suffice. 

Field tests are analytical tests that are normally carried out outside the laboratory (in the field ). Field tests for explosives are usually performed when a rapid, on-site diagnostic detection of explosive materials is required. Thus, they are often carried out on suspects hands and belongings, in post-explosion sites, or in border stations, seaports, and airports. It should be emphasized that they constitute only prehminary examinations, and positive results should not be presented to court unless confirmed by reliable laboratory methods. Because field tests are usually carried out by individuals with no scientific background, their application must be easy, involving simple equipment and methodology. 

The use of default assessment factors is recommended in risk assessments, when justifiable, although the scientific background for such factors in general was considered unsatisfactory. The default assessment factors suggested are summarized in Table 5.2. It is recommended to use assessment factors derived from probabilistic distributions in favor of deterministic assessment factors, see Table 5.2. 

The protein anabolic compounds are most commonly used to stimulate appetite and muscle mass in persons with advanced malignancy or other conditions characterized by advanced malnutrition. These compounds are also often abused by athletes who are trying to build muscle mass. Athletes often take multiple compounds at the same time (stacking) or sequentially to try to maximize their anabolic effects. This type of use is not based on scientific data but rather on hyperbole often spread by individuals with no medical or scientific background. Athletes who use these compounds in this way are unaware of the potential adverse effects or do not care. 

Abstract This chapter comments on the motivations and the methods of crystallographic studies at low temperature. Cry-crystallography is a brunch of Crystallography, a science that is too often confused with a technique. On the other hand, the scientific background to study crystal phases at low temperature is here provided, together with a survey of many possible techniques that provide complementary or supplementary information. Several apphcations are discussed, in particular in relation with highly accurate studies like electron density determination or phase transition mechanisms. 

The use of medicinal herbs for treating human disease started in China thousands of years ago. Eighty percent of the world s population is still using traditional medicine, either because they have no access to Western medicine or choose not to use it. Recently, the use of medicinal herbs, especially Chinese herbs and their products, has attracted considerable attention around the world and generated extensive research on their philosophy, principles, and especially the scientific background of the chemical components responsible for their claimed therapeutic value. 

McClintock and Baker worked together on scientific research projects involving marine organisms of the Antarctic seas, yet they have different scientific backgrounds—McClintock in biology and Baker in chemistry. Is this unusual Explain. 

This is a practical book that can be used by workers with a variety of scientific backgrounds. It... 

Lunenfeld B, Saad F, Hoesl CE. ISA, ISSAM and EAU recommendations for the investigation, treatment and monitoring of late-onset hypogonadism in males scientific background and rationale. Aging Male 2005 8 59-74. 

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