44,800 research outputs found
Airway resistance estimation by best fit analysis in very premature infants
No full textPlethysmographic measurement of airway resistance (R(aw)) has been determined by single-point analysis, usually at 50% of maximum inspiratory flow (MIF). Computer-assisted (best fit) analysis, however, allows R(aw) to be calculated by applying a regression line to any portion of the plethysmograph pressure-flow loop. We determined whether the results of best fit analysis using a computer program, sampling at 200 Hz, were influenced by the portion of the inspiratory loop analysed and if best fit or single-point analysis gave more reproducible results. Twenty infants of median gestational age 26 (range 24-28) weeks, were studied at a median age of 12 (12-14) months corrected for prematurity. R(aw) was calculated by best fit analysis between 0 and 33% MIF, 0 and 50% MIF and 0 and 67% MIF and single-point analysis at 50% of MIF. Similar mean R(aw) values were obtained by best fit analysis between 0 and 33% MIF (2.79 kPa/(l/s)) and 0 and 50% MIF (3.01 kPa/(l/s)) and single-point analysis at 50% MIF (2.86 kPa/(l/s)), but best fit analysis between 0 and 67% gave higher results (3.60 kPa/(l/s)), p < 0.0001. Within the linear portion of the inspiratory loop, the mean intrasubject coefficient of variation was lowest for best fit analysis between 0 and 50% MIF. Best fit computerized analysis between 0 and 50% MIF is recommended as the analysis of choice
Motivated proteins: a web application for studying small three-dimensional protein motifs
No full text<b>BACKGROUND:</b> Small loop-shaped motifs are common constituents of the three-dimensional structure of proteins. Typically they comprise between three and seven amino acid residues, and are defined by a combination of dihedral angles and hydrogen bonding partners. The most abundant of these are alphabeta-motifs, asx-motifs, asx-turns, beta-bulges, beta-bulge loops, beta-turns, nests, niches, Schellmann loops, ST-motifs, ST-staples and ST-turns.We have constructed a database of such motifs from a range of high-quality protein structures and built a web application as a visual interface to this. <b>DESCRIPTION:</b> The web application, Motivated Proteins, provides access to these 12 motifs (with 48 sub-categories) in a database of over 400 representative proteins. Queries can be made for specific categories or sub-categories of motif, motifs in the vicinity of ligands, motifs which include part of an enzyme active site, overlapping motifs, or motifs which include a particular amino acid sequence. Individual proteins can be specified, or, where appropriate, motifs for all proteins listed. The results of queries are presented in textual form as an (X)HTML table, and may be saved as parsable plain text or XML. Motifs can be viewed and manipulated either individually or in the context of the protein in the Jmol applet structural viewer. Cartoons of the motifs imposed on a linear representation of protein secondary structure are also provided. Summary information for the motifs is available, as are histograms of amino acid distribution, and graphs of dihedral angles at individual positions in the motifs. <b>CONCLUSION:</b> Motivated Proteins is a publicly and freely accessible web application that enables protein scientists to study small three-dimensional motifs without requiring knowledge of either Structured Query Language or the underlying database schem
Attached_file-_SupplementaryMaterial – Supplemental material for Scattering-Angle-Resolved Optical Coherence Tomography of a Hypoxic Mouse Retina Model
No full textSupplemental material, Attached_file-_SupplementaryMaterial for Scattering-Angle-Resolved Optical Coherence Tomography of a Hypoxic Mouse Retina Model by Michael R Gardner, Ayesha S Rahman, Thomas E Milner and Henry G Rylander in Journal of Experimental Neuroscience</p
The dialogue between the author and the hero in the “Notes” of G. R. Derzhavin
No full textВ центре внимания автора статьи «Записки» Г. Р. Державина, представляющие по своей сути его автобиографию. Труд этот был создан на закате жизни, он включает все важнейшие события жизни Г. Р. Державина, поэта и государственного деятеля. Рассказ ведется от третьего лица, что придает особую атмосферу повествованию, выстраивается своеобразный диалог между автором и героем, все это и является предметом исследования автора статьи.The focus of the author of the article “Notes” G. R. Derzhavin, representing in essence his autobiography. This work was created at the end of his life; it includes all the most important events in the life of G. R. Derzhavin, poet and statesman. The story is told in a third person, which gives a special atmosphere to the story, a certain dialogue emerges between the author and the hero, all this is the subject of the author's research
Reviving the past : eighteenth-century evangelical interpretations of church history
No full textThis study addresses eighteenth-century English-speaking evangelicals' understandings of church history, through the lens of published attempts to represent preceding Christian centuries panoramically or comprehensively. Sources entail several short reflections on history emerging in the early years of the transatlantic Revival (1730s-1740s) and subsequent, more substantial efforts by evangelical leaders John Gillies, Jonathan Edwards, John Wesley, Joseph and Isaac Milner, and Thomas Haweis. Little scholarly analysis exists on these sources, aside from the renaissance of interest in recent decades in Edwards. This is surprising, considering the acknowledged prominence of history-writing in the eighteenth century and the influence attributed, then and now, to the works of authors such as Gibbon, Hume, and Robertson. The aim is, first, to elucidate each of the above evangelicals' interpretations of the Christian past, both in overview and according to what they said on a roster of particular historical events, people and movements, and then to consider shared and divergent aspects. These aspects range from points of detail to paradigmatic theological convictions. Secondarily, evangelical church histories are analyzed in relation to earlier Protestant as well as eighteenth-century 'enlightened' historiography, in part through attention to evangelical authors' explicit engagement with these currents. This contextualization assists in determining the unique qualities of evangelical interpretations. Is there, then, evidence of a characteristically 'evangelical' perspective on church history? An examination of this neglected area illumines patterns and particulars of evangelicals' historical thought, and these in turn communicate the self-perceptions and the defining features of evangelicalism itself. Findings support the primary contention that evangelical leaders made use of a dynamic pattern of revival and declension as a means of accounting for the full history of Christianity. Beyond displaying the central place of 'revival' for evangelicals, these church histories demonstrate evangelicalism‘s complex relationship—involving both receptivity and critique—with Protestant and Enlightenment currents of historical inquiry
The turtles of the Purbeck Limestone Group of Dorset, southern England
No full textThe turtles from the Purbeck Limestone are revised and it is concluded that there are four shell-based cryptodire species present, namely Pleurosternon bullockii, ‘Glyptops’typocardium comb. nov., Helochelydra anglica comb. nov.,Hylaeochelys latiscutata. There is also one skull-based species, Dorsetochelys delairi, which may prove to be the skull of ‘Glyptops’, Hylaeochelys or an unknown shell-type. All other taxa are junior synonyms except ‘Chelone’obovata Owen, 1842 and Tretosternon punctatum Owen, 1842 which are nomina dubia, the material being unfigured and either lost or incorrectly associated. Other taxonomic conclusions are that (1) because Tretosternon is a nomen dubium, the next senior name for this Purbeck–Wealden genus is Helochelydra Nopcsa, 1928; (2) ‘Pleurosternon’typocardium and ‘Glyptops’ruetimeyeri are synonymous, the senior combination being ‘Glyptops’typocardium; (3) the Purbeck ‘Tretosternon’ material is combined with the holotype and only specimen of Platychelys? anglica as Helochelydra anglica comb. nov.; (4) Hylaeochelys emarginata and H. sollasi are junior synonyms of Hylaeochelys latiscutata; (5) one of Owen's ‘lost’ syntypes of ‘Tretosternon punctatum’ has been recognised and is a plastron of Hylaeochelys latiscutata
Structure motivator: a tool for exploring small three-dimensional elements in proteins
No full text<br>Background:
Protein structures incorporate characteristic three-dimensional elements defined by some or all of hydrogen bonding, dihedral angles and amino acid sequence. The software application, Structure Motivator, allows interactive exploration and analysis of such elements, and their resolution into sub-classes.</br>
<br>Results:
Structure Motivator is a standalone application with an embedded relational database of proteins that, as a starting point, can furnish the user with a palette of unclassified small peptides or a choice of pre-classified structural motifs. Alternatively the application accepts files of data generated externally. After loading, the structural elements are displayed as two-dimensional plots of dihedral angles (φ/ψ, φ/χ1 or in combination) for each residue, with visualization options to allow the conformation or amino acid composition at one residue to be viewed in the context of that at other residues. Interactive selections may then be made and structural subsets saved to file for further sub-classification or external analysis. The application has been applied both to classical motifs, such as the β-turn, and ‘non-motif’ structural elements, such as specific segments of helices.</br>
<br>Conclusions:
Structure Motivator allows structural biologists, whether or not they possess computational skills, to subject small structural elements in proteins to rapid interactive analysis that would otherwise require complex programming or database queries. Within a broad group of structural motifs, it facilitates the identification and separation of sub-classes with distinct stereochemical properties.</br>
(Table 2) Distribution of benthic foraminifers in ODP Hole 125-786A
No full textspecies abundance: A = abundant, C = common, F = few, R = rare, - = absen
(Table 1) Distribution of planktonic foraminifers in ODP Hole 125-786A
No full textspecies abundance: A = abundant, C = common, F = few, R = rare, - = absen
Predicting the conformations of peptides and proteins in early evolution. A review article submitted to Biology Direct
No full textConsidering that short, mainly heterochiral, polypeptides with a high glycine content are expected to have played a prominent role in evolution at the earliest stage of life before nucleic acids were available, we review recent knowledge about polypeptide three-dimensional structure to predict the types of conformations they would have adopted. The possible existence of such structures at this time leads to a consideration of their functional significance, and the consequences for the course of evolution
- …
