Nuclear magnetic resonance studies of the hydration of proteins and DNA

The behaviour of water in the presence of proteins and DNA as elucidated by nuclear magnetic resonance is reviewed. The picture that emerges is that in dilute solution only those water molecules in the interior of the biopolymers or in clefts have their motions substantially affected. In concentrated systems the situation is more complicated because many more motions have to be considered, but there is no evidence of special effects due to the biopolymers being present. The case of nonfreezing water in protein solutions is considered, and it is suggested that this is not evidence for 'bound' water but simply due to the effects of the inhibition of protein precipitation.     

Nutritional requirements of aeromonads and their multiplication in drinking water

Aeromonads can utilize a wide range of low molecular-weight compounds, including amino acids, carbohydrates and long-chain fatty acids at a concentration of a few micrograms per liter. Utilization of biopolymers such as gelatin, casein and amylose is slow at this concentration level. The concentration of substrates available for an A. hydrophila strain in drinking water was usually below 10 micrograms of C/l. The autochthonous bacteria utilized these substrates more rapidly than the aeromonads. The multiplication of aeromonads in drinking water during distribution is therefore explained by their growth on biomass components in the biofilm and in sediments in the pipes.     

Mean Motions in Ptolemy’s <Emphasis Type="Italic">Planetary Hypotheses</Emphasis>

In the Planetary Hypotheses, Ptolemy summarizes the planetary models that he discusses in great detail in the Almagest, but he changes the mean motions to account for more prolonged comparison of observations. He gives the mean motions in two different forms: first, in terms of ‘simple, unmixed’ periods and next, in terms of ‘particular, complex’ periods, which are approximations to linear combinations of the simple periods. As a consequence, all of the epoch values for the Moon and the planets are different at era Philip. This is in part a consequence of the changes in the mean motions and in part due to changes in Ptolemy’s time in the anomaly, but not the longitude or latitude, of the Moon, the mean longitude of Saturn and Jupiter, but not Mars, and the anomaly of Venus and Mercury, the former a large change, the latter a small one. The pattern of parameter changes we see suggests that the analyses that yielded the Planetary Hypotheses parameters were not the elegant trio analyses of the Almagest but some sort of serial determinations of the parameters based on sequences of independent observations.     

Catalysis in abiotic structured media: an approach to selective synthesis of biopolymers

Micro- and nanoenvironments formed by amphiphile self-assembled structures, water-ice lattices and minerals have well-defined, repeating, chemical and physical properties that can be used for selective synthesis of biopolymers, such as RNAs and proteins. The advances made in the development of polymerization supported by these micro- and nanosystems are reviewed here. In particular, it is shown that these systems promote non-enzymatic biopolymerization, yielding long polymers whose sequence composition is determined by the interactions between monomers and the supporting environment. When used to compartmentalize enzymatic biopolymerization, micro- and nanostructures allow the implementation of molecular selection and evolution schemes, which are difficult in homogeneous medium, yielding very active molecules. Thus, micro- and nanoenvironment approaches to the synthesis and selection of biopolymers could be developed into a new biotechnological tool for the production of biopolymers with novel functions.Received 3 August 2004; received after revision 6 October 2004; accepted 21 October 2004     

Solution structure and activity of mouse lysozyme M

The three-dimensional structure of mouse lysozyme M, glycoside hydrolase, with 130 amino acids has been determined by heteronuclear NMR spectroscopy. We found that mouse lysozyme M had four alpha-helices, two 3(10)helices, and a double- and a triple-stranded anti-parallel beta-sheet, and its structure was very similar to that of hen lysozyme in solution and in the crystalline state. The pH activity profile of p-nitrophenyl penta N-acetyl-beta-D-chitopentaoside hydrolysis by mouse lysozyme M was similar to that of hen lysozyme, but the hydrolytic activity of mouse lysozyme M was lower. From analyses of binding affinities of lysozymes to a substrate analogue and internal motions of lysozymes, we suggest that the lower activity of mouse lysozyme M was due to the larger dissociation constant of its enzyme-substrate complex and the restricted internal backbone motions in the molecule.     

On argument ex suppositione falsa

In my opinion it cannot be denied but that your discourse carries with it much of probability, arguing, as we say, ex suppositione, namely, granting that the Earth moves with the two motions assigned it by Copernicus; but, if one excludes those motions, all that you have said is vain and invalid; and for the exclusion of that hypothesis, it is very manifestly hinted by your discourse itself.     

External synchronization of two dynamical systems with uncertain parameters

External synchronization is addressed as two or more dynamical systems with synchronous motions, which is also regarded as master-slave system. In this paper, two dynamical systems, one employs a hysteretic term to model the friction phenomenon, the other involves a hardening stiffness component with the third order of displacement due to flexible deformation, are controlled to converge to the same trajectory. The control strategy is extended from feedback control for all parameters known to adaptive contro...     

Europe's Infrastructure Transition: Economy,War, Nature

In his many uses of the pendulum as a model for other motions, Galileo also described several of the properties of pendular motion. All but a small number of his apparently observational reports ring true because of his use of such qualifiers as ‘almost’. His report of observations of two lead balls on equal long strings is shown by reconstruction to have been a real experiment. His report of similar observations with balls of cork and lead is shown to be an imaginary experiment. His claim that the period of a pendulum is independent of amplitude is shown to be based more on mathematical deduction than on experimental observation.     

Liver enlargement induced by oxythioquinox: effect of the fat content of the diet (author's transl)]

The relationship between the level of lipid calories in the diet and the effects of oxythioquinox, administered at 200 mg/kg fresh food, for 35 days, was studied on the liver enlargment of rat. The results show that the level lipid calories itself have no effect since, in the treated animals, the liver enlargement is due part to an increase of the water content and part to an increase of the size of the cells.     

Hypertrophie du foie provoquée par l'oxythioquinox: Influence du taux de lipides de la ration alimentaire

Summary The relationship between the level of lipid calories in the diet and the effects of oxythioquinox, administered at 200 mg/kg fresh food, for 35 days, wa studied on the liver enlargement of rat. The results show that the level lipid calories itself have no effect since, in the treated animals, the liver enlargement is due part to an increase of the water content and part to an increase of the size of the cells.     

Consensus phylogeny ofDictyostelium

The evolutionary relationship ofDictyostelium discoideum to the yeasts, fungi, plants, and animals is considered on the basis of physiological, morphological and molecular characteristics. Previous analyses of five proteins indicated thatDictyostelium diverged after the yeasts but before the metazoan radiation. However, analyses of the small ribosomal subunit RNA indicated divergence prior to the yeasts. We have extended the molecular phylogenetic analyses to six more proteins and find consistent evidence for a more recent common ancestor with metazoans than yeast. A consensus phylogeny generated from these new results by both distance matrix and parsimony analyses establishesDictyostelum's place in evolution between the yeastsSaccharomyces cerevisiae andSchizzosaccharomyces pombe and the wormCaenorhabditis elegans.     

<Emphasis Type="Italic">Newton's Argument for Proposition 1 of the</Emphasis> Principia

The first proposition of the Principia records two fundamental properties of an orbital motion: the Fixed Plane Property (that the orbit lies in a fixed plane) and the Area Property (that the radius sweeps out equal areas in equal times). Taking at the start the traditional view, that by an orbital motion Newton means a centripetal motion – this is a motion ``continually deflected from the tangent toward a fixed center' – we describe two serious flaws in the Principia's argument for Proposition 1, an argument based on a polygonal impulse approximation. First, the persuasiveness of the argument depends crucially on the validity of the Impulse Assumption: that every centripetal motion can be represented as a limit of polygonal impulse motions. Yet Newton tacitly takes the Impulse Assumption for granted. The resulting gap in the argument for Proposition 1 is serious, for only a nontrivial analysis, involving the careful estimation of accumulating local errors, verifies the Impulse Assumption. Second, Newton's polygonal approximation scheme has an inherent and ultimately fatal disability: it does not establish nor can it be adapted to establish the Fixed Plane Property. Taking then a different view of what Newton means by an orbital motion – namely that an orbital motion is by definition a limit of polygonal impulse motions – we show in this case that polygonal approximation can be used to establish both the fixed plane and area properties without too much trouble, but that Newton's own argument still has flaws. Moreover, a crucial question, haunted by error accumulation and planarity problems, now arises: How plentiful are these differently defined orbital motions? Returning to the traditional view, that Newton's orbital motions are by definition centripetal motions, we go on to give three proofs of the Area Property which Newton ``could have given' – two using polygonal approximation and a third using curvature – as well as a proof of the Fixed Plane Property which he ``almost could have given.' (Received August 14, 2002) Published online March 26, 2003 Communicated by G. Smith     

Peptides and epithelial growth regulation

Summary There is now considerable evidence implicating several peptides in the control of gastrointestinal epithelial cell proliferation and cell renewal. While some of these may act directly, many may be involved in regulating the powerful trophic effects of the intake and digestion of foold on the gut epithelium.—Several peptides have been associated with the regulation of intestinal cell proliferation. There is little doubt that gastrin is trophic to the stomach, but, its role in the rest of the gastrointestinal tract is debatable. Enteroglucagon has often been associated with increased intestinal epithelial proliferation, but at the moment all the evidence for this is circumstantial. The effects of peptide YY and bombesin warrant further study. The availability of recombinant epidermal growth factor (EGF) has recently enabled us to demonstrate a powerful trophic response to infused EGF throughout the gastrointestinal tract. The increasing availability of peptides will eventually allow the rigorous in vivo evaluation of the trophic role of these potentially very important peptides.     

Forecasting with Micro Panels: The Case of Health Care Costs

Micro panels characterized by large numbers of individuals observed over a short time period provide a rich source of information, but as yet there is only limited experience in using such data for forecasting. Existing simulation evidence supports the use of a fixed‐effects approach when forecasting but it is not based on a truly micro panel set‐up. In this study, we exploit the linkage of a representative survey of more than 250,000 Australians aged 45 and over to 4 years of hospital, medical and pharmaceutical records. The availability of panel health cost data allows the use of predictors based on fixed‐effects estimates designed to guard against possible omitted variable biases associated with unobservable individual specific effects. We demonstrate the preference towards fixed‐effects‐based predictors is unlikely to hold in many practical situations, including our models of health care costs. Simulation evidence with a micro panel set‐up adds support and additional insights to the results obtained in the application. These results are supportive of the use of the ordinary least squares predictor in a wide range of circumstances. Copyright © 2016 John Wiley & Sons, Ltd.     

Peptides and epithelial growth regulation

There is now considerable evidence implicating several peptides in the control of gastrointestinal epithelial cell proliferation and cell renewal. While some of these may act directly, many may be involved in regulating the powerful trophic effects of the intake and digestion of food on the gut epithelium. Several peptides have been associated with the regulation of intestinal cell proliferation. There is little doubt that gastrin is trophic to the stomach, but, its role in the rest of the gastrointestinal tract is debatable. Enteroglucagon has often been associated with increased intestinal epithelial proliferation, but at the moment all the evidence for this is circumstantial. The effects of peptide YY and bombesin warrant further study. The availability of recombinant epidermal growth factor (EGF) has recently enabled us to demonstrate a powerful trophic response to infused EGF throughout the gastrointestinal tract. The increasing availability of peptides will eventually allow the rigorous in vivo evaluation of the trophic role of these potentially very important peptides.     

Novel actions of tyrphostin AG 879: inhibition of RAF-1 and HER-2 expression combined with strong antitumoral effects on breast cancer cells

Binding of growth factors to cell surface receptors activates protein tyrosine kinases (PTKs) that initiate cascades of downstream signaling events including the mitogen-activated protein (MAP) kinase cascade. This study reports that the PTK inhibitor AG 879 inhibits proliferation of human breast cancer cells through an effect involving inhibition of MAP kinase activation, but which cannot be explained by effects of AG 879 on its known PTK targets. Instead, AG 879 markedly inhibits expression of the RAF-1 gene, which encodes an upstream MAP kinase kinase kinase. Additionally, expression of HER-2, but not of other genes tested, is inhibited by this compound. These novel effects have to be considered when using AG 879 as a TRK-A and HER-2 inhibitor but may have useful therapeutic implications.     

What’s new in the renin-angiotensin system?

Virtually all existing evidence on the function of angiotensin II (Ang II) in the regulation of tissue homeostasis and blood pressure regulation bears on the more restricted question of what other mechanisms or systems may amplify or inhibit the actions of this important peptide. Whereas there is evidence that Ang II may potentiate the effects of catecholamines, various cytokines and also growth factors, the repertoire of substances which may inhibit the actions of Ang II is more limited and has been restricted primarily to prostacyclin, bradykinin and nitric oxide. Advances in receptor pharmacology and introduction of selective antagonists to two of the receptor subtypes at which Ang II binds permitted a more critical examination of the functions of the renin angiotensin system in physiological and pathophysiological conditions, as well as uncovering the previously unsuspected possibility that within the biochemical pathways leading to the formation of the peptide the renin angiotensin system could process either its immediate precursor (angiotensin I) or the actual Ang II peptide into an alternative form, angiotensin-(1-7) [Ang-(1-7)], the function of which was to antagonize the effects of Ang II. We review here the biological actions of Ang-(1-7) and discuss how this discovery may change altogether the perception of how the renin angiotensin system functions in the regulation of tissue perfusion pressure and the regulation of salt and water metabolism.     

Underdetermination and decomposition in Kepler's Astronomia Nova

This paper examines the underdetermination between the Ptolemaic, Copernican, and the Tychonic theories of planetary motions and its attempted resolution by Kepler. I argue that past philosophical analyses of the problem of the planetary motions have not adequately grasped a method through which the underdetermination might have been resolved. This method involves a procedure of what I characterize as decomposition and identification. I show that this procedure is used by Kepler in the first half of the Astronomia Nova, where he ultimately claims to have refuted the Ptolemaic theory, thus partially overcoming the underdetermination. Finally, I compare this method with other views of scientific inference such as bootstrapping.