bluuebunny/crossref_metadata_2025_split huggingface dataset:
A transitional­combinational theory for the origin of angiosperms
Authors: Stuessy Tod F. 
Published: February 2008

AbstractThe origin of the angiosperms has long remained problematical. Recent new discoveries of early angiosperm fossils and many new molecular phylogenies have helped to identify basal extant angiosperms and to infer their inter­relationships. Still unclear, however, are ties with gymnosperms, both living and fossil. In view of difficulty of finding ancestors for angiosperms, yet also considering their sudden appearance and explosive evolutionary success, a transitional­combinational theory is proposed. This theory suggests that angiosperms evolved slowly from seed ferns in the Jurassic beginning first with the carpel, followed later by double fertilization, and lastly by the appearance of flowers. These three fundamental transitions may have taken more than 100 million years to complete. The extant (or modern) angiosperms did not appear until Early Cretaceous, as attested by micro­ and macrofossils, when the final combination of all three important angiosperm features occurred. This combination provided the opportunity for explosive evolutionary diversification, especially in response to selection from insect pollinators and predators, plus attendant modifications in compatibility and breeding systems. The transitional­combinational theory explains some of the discrepancy between fossil and molecular phylogenetic data, the latter of which suggests that angiosperms originated pre­Cretaceous. DNA (and protein) sequence data and oleananes reflect ancestry in an earlier transitional carpellate lineage (or lineages), much earlier than appearance of the final combination that includes floral and associated pollen modifications. The theory suggests viewing all gymnosperms, other than extinct seed ferns from which carpels arose, as having had no direct phylogenetic connections to modern angiosperms.
The “Invisible” Maya: Minimally Mounded Residential Settlement at Itzán, Petén, Guatemala
Authors: Johnston Kevin J. 
Published: February 2008

AbstractThrough analyses of data recovered at Itzán, Guatemala, this paper examines the architectural morphology and the probable functions of “invisible” building remains in the Maya Lowlands. Invisible building remains are buried, leave no surface traces, and cannot be detected during surface survey, which is the principal settlement detection technique employed by Mayanists. Data at Itzán and other sites suggest that Maya invisible buildings are a more abundant settlement category than many archaeologists have supposed.
Prehistoric Salt Production at El Salado, Veracruz, Mexico
Authors: Santley Robert S. 
Published: February 2008

AbstractEl Salado is a prehispanic salt production site located in the Tuxtla Mountains of southern Veracruz, Mexico. Fieldwork at the site was conducted to determine the methods of salt production, the character of the archaeological residues produced, the scale of the industry, and the history of production. El Salado contains two major occupations, the first dating to the Early Formative period and the second to the Late Classic period. During the Early Formative, solar evaporation in pottery trays was the primary method of salt production. This method was supplemented by some salt-making that involved boiling brine in tecomates. During the Late Classic, in contrast, boiling salt water became the preferred method of production. Late Classic brine reduction involved a two-step process. The salt level in the brine was first increased by boiling in collared jars. This brine was later reduced to loaves by boiling in shallow pottery vessels called cazuelas.
Households, Crafts, and Feasting in the Ancient Andes: The Village Context of Early Nasca Craft Consumption
Authors: Vaughn Kevin J. 
Published: February 2008

AbstractCraft consumption in Early Nasca (ca. A.D. 1–450) society is explored by evaluating the use of polychrome pottery within the context of a residential village. Data are presented from the Early Nasca village, Marcaya, where excavations utilizing a household archaeology approach revealed that most polychromes were consumed by households with high and low status alike, while certain vessel shapes were reserved for high-status households. These findings challenge the common assumption that highly valued crafts were monopolized by elites in middle-range societies, and show instead that there is a potential demand for crafts by both elites and commoners. It is argued that polychrome pottery was broadly used in Nasca because it was integral to ritual consumption that first took place in feasting ceremonies at the regional center Cahuachi, while certain vessel types were restricted to high-status households that acted as intermediaries between Cahuachi and the village.
The Manipulation of Human Remains in Moche Society: Delayed Burials, Grave Reopening, and Secondary Offerings of Human Bones on the Peruvian North Coast
Authors: Millaire Jean-François 
Published: February 2008

AbstractA careful reexamination of funerary contexts suggests that Moche (ca. A.D. 100–800) graves were not simply spaces for the disposal of decaying corpses, but contexts periodically revisited by certain members of Moche society. The dynamic nature of funerary practices is documented through an examination of delayed burials. It is argued that these were the product of two distinct ritual processes, one of which involved the storage of corpses to be used as retainers in subsequent rituals. The practice of grave reopening is also explored, leading to the identification of different types of rituals. At least some graves were reopened to remove skeletal parts of possible potent ancestors. Related ideology is addressed by examining cases of bone destruction and the more common secondary offerings of human remains. This study highlights the dynamic nature of Moche mortuary activity while stressing the important role of those in charge of manipulating ancestors’ remains. Finally, it is argued that the Moche shared with their highland neighbors a common vision of the eternal character of human remains, comparable ritual practices involving the human body, and a similar belief in the capacity of the living to influence the course of their destiny through periodic manipulation of ancestors’ remains.
Evidence for Long-Distance Transportation of Building Stones in the Inka Empire, from Cuzco, Peru to Saraguro, Ecuador
Authors: Ogburn Dennis E. 
Published: February 2008

AbstractEthnohistorical and archaeological data suggest that a collection of more than 450 finely worked Inka building stones found near Saraguro in the southern highlands of Ecuador originated outside that region. The origin of those andesite blocks was investigated via geochemical analysis. Wavelength-dispersive X-ray fluorescence determined the concentrations of nine elements in samples from stones in the Saraguro region and in samples from known Inka andesite quarries at Cojitambo in the southern sierra of Ecuador, and at the Rumiqolqa and Huaccoto quarries near the Inka capital of Cuzco in Peru. The results show that the geochemical composition of the Saraguro stones closely matches that of the Rumiqolqa material, indicating that the Inka had these large andesite blocks moved over a distance of more than 1,600 km, the greatest known distance for the transport of large objects in the precolumbian New World. This endeavor had many implications, including reinforcing state power and ideology, and is also perceived to reflect an imperial “made-work” policy that consumed excess labor through non-utilitarian assignments. These “made-work” projects are best explained as a strategy for reinforcing state control over subject provinces, in contrast to current models of Inka economic organization that focus on efficiency in the use of labor.
Nanocarving of Titania as a Diffusion‐Driven Morphological Instability
Authors: Lee Doh‐Kwon , Janek Juergen 
Published: January 2008

AbstractUnder strongly reducing conditions at high temperatures titania develops a specific surface morphology, comprising a regular array of fibers with a diameter in the sub‐micrometer range. By a chemical diffusion experiment in a defined oxygen potential gradient it is shown that this surface structuring is caused by a diffusion‐driven morphological instability of an advancing reaction front (surface). The kinetics of the process is analyzed in terms of linear transport equations. The conditions for the occurrence of the surface instability are discussed and the required materials properties are analyzed. The observed surface structuring is not restricted to titania, rather it has to occur in all nonstoichiometric compounds with predominant cation mobility.
A Highly Efficient Host/Dopant Combination for Blue Organic Electrophosphorescence Devices
Authors: Lin Jin‐Ju , Liao Wei‐Shieng , Huang Hsiang‐Jung , Wu Fang‐Iy , Cheng Chien‐Hong 
Published: January 2008

AbstractWe have synthesized a new blue‐emitting iridium complex, FIrpytz (iridium(III) bis(4,6‐difluorophenylpyridinato)‐4‐(pyridin‐2‐yl)‐1,2,3‐triazolate), and two new bis(triphenylsilyl) derivatives, BSB (4,4'‐bis‐triphenylsilanyl‐biphenyl) and BST (4,4″‐bis(triphenylsilanyl)‐(1,1′,4′,1″)‐terphenyl) as hosts for blue phosphorescence devices. The photoluminescence (PL) and electroluminescence (EL) properties of different host/dopant combinations were studied in details. These two arylsilanes showed glass transition temperatures (Tgs) ≥ 100 °C higher than those of UGH1 (diphenyl‐di(o‐tolyl)silane) and UGH2 (1,4‐bis(triphenylsilyl)benzene), the common arylsilane‐based hosts. The band gaps for BSB and BST are 4.16 and 3.78 eV, respectively, lower than that of UGH2 of 4.40 eV. The FIrpytz‐doped UGH2, BSB and BST films exhibit PL quantum yields of 0.58, 0.83 and 0.48, respectively. The EL devices using FIrpytz or FIrpic (iridium(III) bis(4,6‐difluorophenylpyridinato)‐picolinate) as the blue phosphorescence dopants and UGH2, BSB and BST as the hosts also showed that BSB‐based devices gave the best device efficiencies. Both PL and EL studies show that BSB is better than UGH2 and BST as the host material for FIrpytz and FIrpic. In particular, the use of FIrpytz as dopant, BSB as host and LiF/Al as cathode provides a remarkably efficient combination for blue electrophosphorescence device reaching a very high external quantum efficiency of 19.3% at 8.5 V and a high luminance level of 20500 cd m−2 at 19.3 V after electroluminescence started at 5.1 V.
Lokale Lasteintragung über Bolzenverbindungen in dünne Bauteile aus textilbewehrtem Beton
Authors: Jesse Dirk , Jesse Frank , Curbach Manfred 
Published: January 2008

AbstractDie Einleitung von Lasten über stabförmige Verbindungsmittel ist vor allem aus dem Stahlbau und Holzbau bekannt. Es ist eine einfache Möglichkeit zur Verbindung platten‐ und scheibenartiger Bauteile. Im Rahmen der vorliegenden Studie wird die Anwendungsmöglichkeit stabförmiger Verbindungsmittel (Bolzen) für dünne Betonbauteile mit textiler Bewehrung untersucht. Es soll geklärt werden, wie eine einfache, robuste und effiziente Lasteinleitung in dünne bewehrte Betonscheiben realisiert werden kann. Dazu wurde an insgesamt 36 Einzelversuchen das Tragverhalten der Verbindung in Abhängigkeit von den Parametern Randabstand, Bewehrungsgrad bzw. Lagenanzahl und Orientierung der Bewehrung untersucht. Aufgrund der geplanten Anwendung begrenzen sich die Untersuchungen auf eine Belastung in Scheibenebene. Anhand eines Stabwerkmodells werden die Versagensmechanismen und ‐formen beschrieben.
Serielle Stückfertigung von Bauteilen aus textilbewehrtem Beton
Authors: Brameshuber Wolfgang , Mott Rebecca , Hegger Josef , Voss Stefan , Gries Thomas , Barlé Marijan , Böhm Stefan , Hartung Ilko 
Published: January 2008

AbstractIm Rahmen des AiF‐Forschungsvorhabens wurden Produktionsverfahren zur stückweisen Herstellung von Bauteilen aus textilbewehrtem Beton untersucht. Zum Forschungsumfang gehörten die Herstellverfahren Laminieren, Gießen, Spritzen und Schleudern sowie Kombinationen der Verfahren. Neben der Anpassung der Feinbetonmischung und Textilien an das jeweilige Verfahren sowie der Entwicklung benötigter Abstandhalter wurden unter Verwendung ausgesuchter Produktionstechniken Musterbauteile hergestellt, um den vollständigen Fertigungsablauf der Bauteile untersuchen zu können. Dazu zählten die Wahl des geeigneten Produktionsverfahrens, die Bemessung der Bauteile, die Konfektionierung der Textilien, die Herstellung der Bauteile sowie deren Prüfung und Diskussion der Ergebnisse. Dieser Ablauf wurde exemplarisch für die Fertigung von Schleuderbetonrohren sowie für Elemente der bauteilintegrierten Schalung durchgeführt.
Vereinfachte Berechnung von Stahlbetonstützen unter Brandbeanspruchung
Authors: Quast Ulrich , Richter Ekkehard 
Published: January 2008

AbstractDie Brandschutz‐Teile der Eurocodes regeln auch die Berechnungen des Feuerwiderstands. Solche Berechnungen waren in der Praxis bisher unüblich. Die thermische Analyse kann durch Vorgabe der Temperaturprofile in den Querschnitten ersetzt werden. Es wird gezeigt, wie dann die mechanische Analyse für eine Stahlbetonstütze nach Theorie 2. Ordnung durchgeführt werden kann.
Buchbesprechung: Vom Beton‐Eisen zum Spannbeton
Authors: Schlaich Jörg 
Published: January 2008

AbstractEine Entwicklungsgeschichte unter besonderer Berücksichtigung der Verhältnisse Österreichs. Anlässlich des Jubiläums 100 Jahre Österreichische Vereinigung für Beton‐ und Bautechnik sind zwei Bücher erschienen:– Die Entwicklung der Österreichischen Bautechnik– Vom Beton‐Eisen zum Spannbeton
Discovery of high‐affinity peptide ligands for vancomycin
Authors: Yao Nianhuan , Wu Chun‐Yi , Xiao Wenwu , Lam Kit S. 
Published: February 2008

AbstractVancomycin, an important antibiotic against medically relevant gram‐positive bacteria such as methicillin‐resistant Staphylococcus aureus, exerts its antibacterial effects by binding with moderate affinity to the C‐terminal Lys‐D‐Ala‐D‐Ala motif (Kaa) of the bacterial cell wall peptide precursor. Essential for Kaa binding to vancomcyin is the free‐carboxyl group on the terminal D‐Ala in Kaa. In efforts to identify other Kaa‐based peptides which bind vancomycin with higher affinity, we utilized our one‐bead‐one‐compound (OBOC) combinatorial library approach, a method which has been widely used to discover highly specific ligands against various receptors. In standard OBOC peptide libraries, the C‐terminal end of the synthesized peptide is tethered to a solid‐support/resin, however, this study reports development of a synthetic strategy for generating OBOC peptide libraries with a free D‐Ala‐D‐Ala carboxyl end. We screened these “OBOC inverted” peptide libraries against vancomycin, and discovered a series of peptide ligands with strong consensus, which bind vancomycin. To further optimize these ligands, two highly focused Kaa‐containing OBOC combinatorial peptidomimetic libraries were designed, synthesized, and screened against vancomycin under more stringent conditions. Peptidomimetic ligands which bind vancomycin with higher affinity than Kaa were identified. The dissociation constant of one of these ligands, Lys(Ac)‐HOCit‐Glu‐Cha‐Lys(3,5‐dihydroxybenzoyl)‐D‐Ala‐D‐Ala (9), as determined by surface plasmon resonance, was 1.03 μM, roughly a 50‐fold improvement in affinity compared to Kaa (KD = 50 μM). © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 421–432, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Effect of humic acids on electricity generation integrated with xylose degradation in microbial fuel cells
Authors: Huang Liping , Angelidaki Irini 
Published: February 2008

AbstractPentose and humic acids (HA) are the main components of hydrolysates, the liquid fraction produced during thermohydrolysis of lignocellulosic material. Electricity generation integrated with xylose (typical pentose) degradation as well as the effect of HA on electricity production in microbial fuel cells (MFCs) was examined. Without HA addition the maximum power density increased from 39.5 mW/m2 to 83 mW/m2 when initial xylose concentrations increased from 1.5 to 30 mM, while coulombic efficiency ranged from 13.5% to 52.4% for xylose concentrations of 15 and 0.5 mM, respectively. Compared to controls where HAs were not added, addition of commercial HA resulted in increase of power density and coulombic efficiency, which ranged from 7.5% to 67.4% and 24% to 92.6%, respectively. Digested manure wastewater (DMW) was tested as potential mediator for power generation due to its content of natural HA, and although it could produce higher coulombic efficiency namely 32.2% than the control of 18.3%, showed lower power density which was approx. 57 mW/m2 in comparison to power density of the control which was 69 mW/m2. Presence of commercial HA or DMW in the anode chamber resulted in faster xylose degradation and formation of more oxidized products (acetate and formate) as well as less reduced products (lactate and ethanol) compared to the controls. The reduced power generation in the presence of DMW was attributed to the presence of bacterial inhibitors such as phenolic compounds. Therefore, new feedstocks for MFCs, containing both mediators and substrates, such as lignocellulose hydrolysates should be considered for their applicability in MFCs. Biotechnol. Bioeng. 2008;100: 413–422. © 2008 Wiley Periodicals, Inc.
Production of recombinant proteins in clonal root cultures using episomal expression vectors
Authors: Skarjinskaia Marina , Karl Jason , Araujo Adriana , Ruby Karen , Rabindran Shailaja , Streatfield Stephen J. , Yusibov Vidadi 
Published: February 2008

AbstractWe have developed a fully contained system for expressing recombinant proteins that is based on clonal root cultures and episomal expression vectors. Clonal root lines expressing green fluorescent protein (GFP) or human growth hormone were generated from Nicotiana benthamiana leaves infected with the tobacco mosaic virus‐based vector 30B after exposure to Agrobacterium rhizogenes. These lines accumulated GFP at over 50 mg per kg fresh tissue, a level that is comparable with other plant production systems in early stage development. Accumulation of both hGH and GFP in the clonal root lines was sustained over a 3‐year period, and in the absence of antibiotic selection. This technology shows promise for commercial production of vaccine antigens and therapeutic proteins in contained facilities. Biotechnol. Bioeng. 2008;100: 814–819. © 2008 Wiley Periodicals, Inc.
Determination of the cytosolic free NAD/NADH ratio in Saccharomyces cerevisiae under steady‐state and highly dynamic conditions
Authors: Canelas André B. , van Gulik Walter M. , Heijnen Joseph J. 
Published: February 2008

AbstractThe coenzyme NAD plays a major role in metabolism as a key redox carrier and signaling molecule but current measurement techniques cannot distinguish between different compartment pools, between free and protein‐bound forms and/or between NAD(H) and NADP(H). Local free NAD/NADH ratios can be determined from product/substrate ratios of suitable near‐equilibrium redox reactions but the application of this principle is often precluded by uncertainties regarding enzyme activity, localization and coenzyme specificity of dehydrogenases. In Saccharomyces cerevisiae, we circumvented these issues by expressing a bacterial mannitol‐1‐phosphate 5‐dehydrogenase and determining the cytosolic free NAD/NADH ratio from the measured [fructose‐6‐phosphate]/[mannitol‐1‐phosphate] ratio. Under aerobic glucose‐limited conditions we estimated a cytosolic free NAD/NADH ratio between 101(±14) and 320(±45), assuming the cytosolic pH is between 7.0 and 6.5, respectively. These values are more than 10‐fold higher than the measured whole‐cell total NAD/NADH ratio of 7.5(±2.5). Using a thermodynamic analysis of central glycolysis we demonstrate that the former are thermodynamically feasible, while the latter is not. Furthermore, we applied this novel system to study the short‐term metabolic responses to perturbations. We found that the cytosolic free NAD–NADH couple became more reduced rapidly (timescale of seconds) upon a pulse of glucose (electron‐donor) and that this could be reversed by the addition of acetaldehyde (electron‐acceptor). In addition, these dynamics occurred without significant changes in whole‐cell total NAD and NADH. This approach provides a new experimental tool for quantitative physiology and opens new possibilities in the study of energy and redox metabolism in S. cerevisiae. The same strategy should also be applicable to other microorganisms. Biotechnol. Bioeng. 2008;100: 734–743. © 2008 Wiley Periodicals, Inc.
Use of Amplatzer occlusion devices to occlude Fontan baffle leaks during fenestration closure procedures
Authors: Crowley David I. , Donnelly Jon P. 
Published: January 2008

AbstractThe authors describe the use of Amplatzer occlusion devices to successfully occlude Fontan baffle leaks in three patients. These additional right to left shunts were recognized at the time of elective transcatheter closure of surgically created fenestrations. A common site of baffle leak is described at the base of the right atrial appendage. This suture line serves to exclude the right atrial appendage from Fontan baffle flow and lies within the corrugated surface of the pectinate muscles, making it particularly vunerable to baffle leaks over time. © 2008 Wiley‐Liss, Inc.
Lengthening of proximal implantation site during endovascular repair of thoracic aortic aneurysm: Preservation of carotid patency with retrograde trans endograft deployment of a carotid stent
Authors: Eid‐Lidt Guering , Ramirez Samuel , Gaspar Jorge 
Published: January 2008

AbstractEndovascular repair of descending thoracic aortic aneurysms with a reduced proximal implantation site represents a technical challenge. Surgical procedures before endovascular exclusion can be necessary to increase the length of the proximal landing site to avoid type 1 endoleaks. We present a case of endovascular exclusion of a descending thoracic aortic aneurysm with the endograft placed proximal to the left common carotid artery. Flow to this arch was preserved reconstructing the carotid ostium with the retrograde implantation of a carotid stent that was placed extending across an orifice created in the deployed endograft by puncture and balloon dilatation. © 2008 Wiley‐Liss, Inc.
Influence of Rheological Behavior of Purely Viscous Fluids on Analytical Residence Time Distribution in Straight Tubes
Authors: Delaplace G. , Thakur R. K. , Bouvier L. , Leprêtre C. , Ilnyzckyj C. , André C. , Nouar C. 
Published: January 2008

AbstractIn an effort to better understand the homogeneity of heat treatment of foodstuffs in holding tubes, the cumulative residence time distribution function is derived for a Herschel‐Bulkley fluid from fully developed laminar flow in a straight circular tube under isothermal conditions when diffusional effects are negligible. The proposed analytical solution can be reduced to solutions for Newtonian, shear‐thinning, dilatant, Bingham fluids by setting particular rheological parameters, and consequently, it is possible to successfully explain the dependence of residence time distribution on fluid properties for almost all of the rheological models used for time‐independent purely viscous fluids.