210,841 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Letter from Dugan & Wall to B. F. Dowell, 1868
No full textLeft letter from Dugan & Wall. Enclosed vouchers against Indian services in California
The effects of environmental history and thermal stress on coral physiology and immunity
No full textThis dataset has all data for the manuscript (Wall CB, CA Ricci, GE Foulds, LD Mydlarz, RD Gates, HM Putnam (2018) The effects of environmental history and thermal stress on coral physiology and immunity. Marine Biology). Data included a zipped archive shape file for creating Kāne'ohe Bay map, physical data (light and temperature) from Kāne'ohe Bay and laboratory experiments, pCO2 data for Kāne'ohe Bay reef sites dowloaded from NOAA PMEL, and biological responses (PAM fluorometry, physiology, immune activity and oxidative profile)
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
One-loop operator matching in the static heavy and domain-wall light quark system with O(a) improvement
No full textWe discuss perturbative O(g2a) matching with static heavy quarks and domainwall light quarks for lattice operators relevant to B-meson decays and B0–¯B 0 mixing. The chiral symmetry of the light domain-wall quarks does not prohibit operator mixing at O(a) for these operators. The O(a) corrections to physical quantities are non-negligible and must be included to obtain high-precision simulation results for CKM physics. We provide results using plaquette, Symanzik, Iwasaki and DBW2 gluon actions and applying APE, HYP1 and HYP2 link-smearing for the static quark action
Cell wall assembly in Bacillus megaterium: incorporation of new peptidoglycan by a monomer addition process
No full textThe pattern of cross-linking in the peptidoglycan of Bacillus megaterium has been studied by the pulsed addition of radiolabeled diaminopimelic acid. The distribution of label in muropeptides, generated by digestion with Chalaropsis muramidase and separated by high-performance liquid chromatography, stabilized after 0.15 of a generation time. The proportion of label in the acceptor and donor positions of isolated muropeptide dimers stabilized over the same period of time. The results have led to the formulation a new model for the assembly of peptidoglycan into the cylindrical wall of B. megaterium by a monomer addition process. Single nascent glycan peptide strands form cross-linkages only with material at the inner surface of the wall. Maturation is a direct consequence of subsequent incorporation of further new glycan peptide strands, and there is no secondary cross-linking process. The initial distribution of muropeptides is constant. It follows that the final pattern of cross-linking in the wall is determined solely by, and can be forecast from, this repetitive pattern of incorporation. In a modified form, this model can also be applied to assembly of cell walls in rod-shaped gram-negative bacteria
Bacterial glycobiology: rhamnose-containing cell wall polysaccharides in Gram-positive bacteria.
No full textThe composition of the Gram-positive cell wall is typically described as containing peptidoglycan, proteins and essential secondary cell wall structures called teichoic acids, which comprise approximately half of the cell wall mass. The cell walls of many species within the genera Streptococcus, Enterococcus and Lactococcus contain large amounts of the sugar rhamnose, which is incorporated in cell wall-anchored polysaccharides (CWP) that possibly function as homologues of well-studied wall teichoic acids (WTA). The presence and chemical structure of many rhamnose-containing cell wall polysaccharides (RhaCWP) has sometimes been known for decades. In contrast to WTA, insight into the biosynthesis and functional role of RhaCWP has been lacking. Recent studies in human streptococcal and enterococcal pathogens have highlighted critical roles for these complex polysaccharides in bacterial cell wall architecture and pathogenesis. In this review, we provide an overview of the RhaCWP with regards to their biosynthesis, genetics and biological function in species most relevant to human health. We also briefly discuss how increased knowledge in this field can provide interesting leads for new therapeutic compounds and improve biotechnological applications
A critical review of the standards and design processes for motorway diverges in the UK
No full textThis paper contains a critical review of design standards for motorway diverges in the UK over the last 40 years. These standards have been progressively updated at regular intervals and their evolving nature has been assessed. Most changes have been minor as a result of changes to traffic flow, driver behaviour or vehicle performance. A brief comparison has also been made between standards for diverges in the UK and those in other selected EU countries. This paper particularly focuses on the diverging flow-region diagram contained in the latest Government Standard TD22/92 ‘The Layout of Grade-Separated Junctions’. This diagram is used by traffic engineers as a tool in order to select the most appropriate diverge layout for a particular site. The historical background leading to its derivation is reviewed along with a discussion of comments made by five practicing traffic engineers as to its effectiveness and usage. These comments have been used along with other analysis to make recommendations as to how the diagram should be interpreted and how it could be improved
Cell wall involvement in desiccation tolerance in the resurrection plant Craterostigma wilmsii
No full textBibliography: leaves 92-129.Resurrection plants have the unique capacity to revive from an air-dried state. In order to cope with desiccation, resurrection plants have to overcome a number of stresses, mechanical stress being one. This occurs when the cytoplasm shrinks creating tension between the plasma membrane and the cell wall. In leaves of the Craterostigma species, an extensive shrinkage occurs during drying as well as a considerable wall folding. It is thought that this folding is a well controlled process rather than a simple collapse and that the ability of the wall to fold is important for the viability of the tissues upon drying. The aim of this study was to characterize the cell wall architecture and composition in hydrated and dry leaves of C. wilmsii using microscopical and biochemical techniques. Calcium and hormone contents were also determined during drying. The development of anhydrous fixation for microscopy confirmed the important folding of the wall previously observed with chemical fixation. Using immunocytochemical techniques and a variety of well characterized antibodies, the nature and composition of wall polymers was investigated. There was nothing unusual in the wall composition of C. wilmsii leaves as compared with other dicotyledonous plants. The results show a significant increase of the hemicellulosic polysaccharide xyloglucan and of the unesterified pectins during drying with levels declining again during rehydration. In contrast no increase was observed in others polysaccharides such as ß (1-4) galactans and methylesterified pectins. Biochemical analysis allowed further characterization of cell wall composition of C. wilmsii. The data demonstrate marked changes in the pectic and hemicellulosic wall fraction from dry plants compared to hydrated ones. The most conspicuous change was a decrease in glucose content in the hemicellulose fraction of the dry plant. Together these findings show that dehydration causes important alteration of polysaccharides content in the cell wall of C. wilmsii. Such modifications might be involved in the modulation of the mechanical properties of the wall during dehydration. Furthermore calcium ions content was shown to increase in the cell wall of dry plants, this could also have a role in stabilizing the wall architecture. All these alterations might be under the control of auxin, an hormone whose content was shown to increase during dehydration
Letter from B. F. Dowell to the Commissioner of Indian Affairs with a letter from Dugan & Wall, 1867
No full textEnclosed a letter from Dugan & Wall with vouchers for payment for Indian service in California
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