bluuebunny/crossref_metadata_2025_split huggingface dataset:
System for combined three‐dimensional morphological and molecular analysis of thick tissue specimens
Authors: Fernandez‐Gonzalez Rodrigo , Jones Arthur , Garcia‐Rodriguez Enrique , Chen Ping Yuan , Idica Adam , Lockett Stephen J. , Barcellos‐Hoff Mary Helen , Ortiz‐De‐Solorzano Carlos 
Published: December 2002

AbstractWe present a new system for simultaneous morphological and molecular analysis of thick tissue samples. The system is composed of a computer‐assisted microscope and a JAVA‐based image display, analysis, and visualization program that allows acquisition, annotation, meaningful storage, three‐dimensional reconstruction, and analysis of structures of interest in thick sectioned tissue specimens. We describe the system in detail and illustrate its use by imaging, reconstructing, and analyzing two complete tissue blocks that were differently processed and stained. One block was obtained from a ductal carcinoma in situ (DCIS) lumpectomy specimen and stained alternatively with Hematoxilyn and Eosin (H&E), and with a counterstain and fluorescence in situ hybridization (FISH) to the ERB‐B2 gene. The second block contained a fully sectioned mammary gland of a mouse, stained for histology with H&E. We show how the system greatly reduces the amount of interaction required for the acquisition and analysis and is, therefore, suitable for studies that require morphologically driven, wide‐scale (e.g., whole gland) analysis of complex tissue samples or cultures. Microsc. Res. Tech. 59:522–530, 2002. Published 2002 Wiley‐Liss, Inc.
Determination of chloride efflux by X‐ray microanalysis versus MQAE‐fluorescence
Authors: Andersson Charlotte , Roomans Godfried M. 
Published: December 2002

AbstractThe importance of chloride channels for the cell is demonstrated by a number of serious human diseases that are due to mutations in chloride channels. The most well‐known of these diseases is cystic fibrosis. Investigations into the mechanisms of the disease and possible treatments require the study of chloride fluxes at the level of individual cells. The present study compares two methods for studies of chloride transport: X‐ray microanalysis and MQAE fluorescence with image analysis. As an experimental system, the cAMP‐activated chloride channel in cultured respiratory epithelial cells was chosen. Both methods showed that stimulation with the cAMP‐elevating agents forskolin and IBMX decreased the chloride content of the cells by about 20–27%. Inducing a driving force for chloride by replacing extracellular chloride by nitrate resulted in a chloride efflux that was significantly increased in the presence of forskolin and IBMX. This study shows that X‐ray microanalysis and MQAE fluorescence are adequate and comparable methods for measuring cAMP‐dependent chloride transport in individual cells. Microsc. Res. Tech. 59:531–535, 2002. © 2002 Wiley‐Liss, Inc.
Confocal laser scanning microscopy to study formation and properties of polyelectrolyte nanocapsules derived from CdCO3 templates
Authors: Silvano D. , Krol S. , Diaspro A. , Cavalleri O. , Gliozzi A. 
Published: December 2002

AbstractThree‐dimensional confocal laser scanning microscopy (CLSM) was used as an essential investigation method to obtain information about the formation and morphological characteristics of nanocapsules. Nanocapsules are built by layer‐by‐layer deposition of alternatively charged polyelectrolytes on templates forming nanostructured hollow shells. CLSM is unique in allowing for monitoring of the core dissolution process in real time and for studying nanocapsule functioning in hydrated conditions within a three‐dimensional and temporal framework. Since we are also interested in the identification of other possible templates, we briefly report on the use of yeast cells as biocolloidal cores monitored by means of two‐photon microscopy. Here we focus our attention on the use of CdCO3 crystals as template candidates for the preparation of stable capsules. Both cubic and spherical CdCO3 cores have been produced. Cubic cores exhibit higher monodispersity and smaller size compared to spherical ones. Capsules templated on these cores have a higher surface‐to‐volume ratio that is valuable for applications related to drug delivery, functional properties of the shells and adsorption of proteins, and other biologically relevant molecules. Microsc. Res. Tech. 59:536–541, 2002. © 2002 Wiley‐Liss, Inc.
Further structures in the jaw apparatus of limnognathia maerski (micrognathozoa), with notes on the phylogeny of the gnathifera
Authors: Sørensen Martin Vinther 
Published: December 2002

AbstractThe jaws of Limnognathia maerski, Micrognathozoa, were investigated with light‐ and scanning electron microscopy. The study yielded several new structures and sclerites, including the ventral part of main jaw, the pharyngeal lamellae, the manus, the dorsal and ventral fibularium teeth, and a reinterpretation of the fibularium compartmentalization. Furthermore, it was shown that several jaw elements are composed of densely packed rods. Comparison with Rotifera and Gnathostomulida suggested that the micrognathozoan main jaw is homologous with the rotifer incus and the gnathostomulid articularium and that the pseudophalangids (the ventral jaws) and their associated sclerites correspond to the rotifer mallei. These results imply that Micrognathozoa is more closely related to Rotifera than to Gnathostomulida. J. Morphol. 255:131–145, 2003. © 2002 Wiley‐Liss, Inc.
Embryonic and larval staging of summer flounder (paralichthys dentatus)
Authors: Martinez Gabriela M. , Bolker Jessica A. 
Published: December 2002

AbstractEarly development of flatfishes such as the summer flounder Paralichthys dentatus (Pleuronectiformes) has not been extensively documented, largely because of a dearth of material; however, the recent expansion of flatfish aquaculture has made embryos of P. dentatus readily available for developmental studies. We divide development of P. dentatus embryos and larvae into two main periods, pre‐ and posthatching, and assign stages within each of those primary divisions. Stages from fertilization to hatching loosely follow the general teleost staging scheme suggested by Shardo ([1995] J Morphol 225:125–167); stages from hatching through metamorphosis are aligned with the series used for Japanese flounder, P. olivaceus (Minami [1982] Nippon Suisan Gakkaishi 48:1581–1588; Fukuhara [1986] Nippon Suisan Gakkaishi 52:81–91). Although length, width, and age may serve as approximate indicators of developmental progression in summer flounder, these characteristics are too variable to form the sole basis of a staging table. Therefore, we define stages by morphological criteria drawn from the development of the jaw apparatus and digestive system, eye migration, and notochord tip flexion. Examination of these morphological features in hatched larvae allows accurate and consistent assessment of developmental stage despite variation in timing and size. The staging scheme for flounder embryonic and larval development presented here should facilitate both experimental and comparative research on summer flounder and other flatfish species. J. Morphol. 255:162–176, 2003. © 2002 Wiley‐Liss, Inc.
Innovation is not enough: climates for initiative and psychological safety, process innovations, and firm performance
Authors: Baer Markus , Frese Michael 
Published: December 2002

AbstractThis paper contributes to the discussion on contingencies of process innovations by focusing on and introducing organizational‐level constructs of climate for initiative and psychological safety. We argue that process innovations, defined as deliberate and new organizational attempts to change production and service processes, need to be accompanied by climates that complement the adoption and implementation of such innovations. Our study of 47 mid‐sized German companies examines the relation between process innovations, climates for initiative and psychological safety, and firm performance. Results show that climates for initiative and psychological safety were positively related to two measures of firm performance—longitudinal change in return on assets (holding prior return on assets constant) and firm goal achievement—and moderated the relation between process innovations and firm performance. Copyright © 2003 John Wiley & Sons, Ltd.
Influence tactics and work outcomes: a meta‐analysis
Authors: Higgins Chad A. , Judge Timothy A. , Ferris Gerald R. 
Published: December 2002

AbstractRecent research on influence tactics has focused on the benefits that accrue as a result of using such tactics. The current study utilizes meta‐analytic techniques to estimate the true population correlations between various influence tactics and work‐related outcomes. Results indicate that ingratiation and rationality have positive effects on work outcomes. Additional analyses suggest that these and other influence tactics have significant effects in certain situations and on specific work outcomes. Copyright © 2003 John Wiley & Sons, Ltd.
Late Wisconsin periglacial environments of the southern margin of the Laurentide Ice Sheet reconstructed from pollen analyses
Authors: Heusser Linda , Maenza‐Gmelch Terryanne , Lowell Thomas , Hinnefeld Rebecca 
Published: December 2002

AbstractFull‐glacial pollen assemblages from four radiocarbon‐dated interstadial deposits in southwestern Ohio and southeastern Indiana imply the presence of herbaceous vegetation (tundra or muskeg with subarctic indicator Selaginella selaginoides) on the southern margin of the Miami lobe of the Laurentide Ice Sheet ca. 20 000 14C yr BP. Scattered Picea (spruce) and possibly Pinus (pine) may have developed regionally ca. 19 000 14C yr BP, and ca. 18 000 14C yr BP, respectively. Spruce stumps in growth position support a local source of pollen. Prior to the ca. 14 000 14C yr BP glacial advance, small amounts of Quercus (oak) and other deciduous pollen suggest development of regional boreal (conifer–hardwood) forests. Copyright © 2002 John Wiley & Sons, Ltd.
High‐resolution study of Icelandic tephras in the Kangerlussuaq Trough, southeast Greenland, during the last deglaciation
Authors: Jennings Anne E. , Grönvold Karl , Hilberman Rachael , Smith Mikie , Hald Morten 
Published: December 2002

AbstractTephra abundance data and geochemistry in Late‐glacial and Holocene sediments on the East Greenland shelf are presented. Two well‐known tephras were identified from electron microprobe analysis of tephra shards picked from ash peaks in the cores. These are the Vedde Ash and Saksunarvatn Ash, which probably were deposited on the shelf after transport on drifting ice. The radiocarbon dates (marine reservoir corrected by −550 yr) that constrain the timing of deposition of the tephra layers compare well with the terrestrial and ice‐core ages of the tephras without requiring additional reservoir correction to align them with the known tephra ages. Several prominent tephra layers with a composition of Ash Zone 2 tephra punctuate the deglacial sediments. These tephra peaks coincide with significant light stable isotope events (signifying glacial meltwater) and fine‐grained sediments poor in ice‐rafted detritus. We interpret the Ash Zone 2 tephra peaks as sediment released from the Greenland Ice Sheet during strong melting pulses of the deglaciation. Copyright © 2002 John Wiley & Sons, Ltd.
European quaternary refugia: a factor in large carnivore extinction?
Authors: O'Regan Hannah J. , Turner Alan , Wilkinson David M. 
Published: December 2002

AbstractThe extinction of large carnivores in Europe during the Quaternary is reviewed and the potential role of glacial refugia in these extinctions is investigated using the VORTEX model for population viability analysis. A model was built for a medium sized big cat similar to the extinct Panthera gombaszoegensis utilising life history data from the modern jaguar Panthera onca. This approach highlighted the potential importance of glacial refugia in the extinction process. Even model refugia the size of the Italian peninsula did not guarantee persistence of a population over a 1000 yr time span, illustrating the role of chance in survival in such a refugium. An area the size of the largest Mediterranean island was unable to support a big cat population for a period of 1000 yr. The models also demonstrated the importance of inbreeding as a mechanism for extinction in refugia. It is suggested that repeated genetic bottlenecks during successive glaciations would tend to remove lethal recessive alleles from the population, increasing the probability of survival in refugia in subsequent glaciations. The history of extinction of large carnivores in the European Quaternary is interpreted in the light of these results. Copyright © 2002 John Wiley & Sons, Ltd.
Fission‐track dating of a tephra layer related to Poti‐Malal and Seguro drifts in the Río Grande basin, Mendoza, Argentina
Authors: Espizua Lydia E. , Bigazzi Giulio , Iunes Pedro J. , Hadler Julio C. , Osorio Ana Maria 
Published: December 2002

AbstractTwo old drift units called Poti‐Malal and Seguro have been differentiated in the Río Grande basin based on relative‐age criteria, stratigraphical relationships, morphology and fission‐track dating. A tephra dated at 0.226 ± 0.025 Ma was deposited on the Poti‐Malal drift and underlies the Seguro outwash, which is inferred to equate with marine oxygen isotope stage 6. The stratigraphical position and age suggest that the tephra post‐dates the Poti‐Malal glaciation and that it is older than the Seguro drift. The Poti‐Malal glaciation must be at least as old as Early–Middle Pleistocene, and the Seguro glaciation is assigned to the penultimate glaciation. The tephra unit may have been deposited during marine oxygen isotope stage 7. Copyright © 2002 John Wiley & Sons, Ltd.
Early to middle Holocene silicic tephra horizons from the Katla volcanic system, Iceland: new results from the Faroe Islands
Authors: Wastegård Stefan 
Published: December 2002

AbstractComparatively few Icelandic tephra horizons dated to the early part of the Holocene have so far been detected outside Iceland. Here, I present several tephra horizons that have been recorded in a Holocene peat sequence on the Faroe Islands. Geochemical analyses show that at least two dacitic and one rhyolitic tephra layers were erupted from the Katla volcanic system on southern Iceland between ca. 8000 and 5900 cal. yr BP. The upper two layers can be correlated with the SILK tephras described from southern Iceland, whereas the third, dated to ca. 8000 cal. yr BP, has a geochemistry virtually identical to the rhyolitic component of the Vedde Ash. The results suggest that the Late Weichselian and early Holocene eruption history of the Katla volcano was probably more complex than inferred from Iceland. A new, early Holocene rhyolitic tephra dated to ca. 10 500 cal. yr BP probably originates in the Snæfellsnes volcanic centre in western Iceland. These new findings may play an important role in developing a Holocene tephra framework for northwest Europe. Copyright © 2002 John Wiley & Sons, Ltd.
Distribution, sediment magnetism and geochemistry of the Saksunarvatn (10 180 ± 60 cal. yr BP) tephra in marine, lake, and terrestrial sediments, northwest Iceland
Authors: Andrews John T. , Geirsdóttir Aslaug , Hardardóttir Jórunn , Principato Sarah , Grönvold Karl , Kristjansdóttir Gréta B. , Helgadóttir Gudrún , Drexler John , Sveinbjörnsdóttir Arny 
Published: December 2002

AbstractIn 1997, seismic surveys in the troughs off northwest and north Iceland indicated the presence of a major, regional sub‐bottom reflector that can be traced over large areas of the shelf. Cores taken in 1997, and later in 1999 on the IMAGES V cruise, penetrated through the reflector. In core MD99‐2269 in Húnaflóaáll, this reflector is shown to be represented by a basaltic tephra with a geochemical signature and radiocarbon age correlative with the North Atlantic‐wide Saksunarvatn tephra. We trace this tephra throughout northwest Iceland in a series of marine and lake cores, as well as in terrestrial sediments; it forms a layer 1 to 25 cm thick of fine‐ to medium‐grained basaltic volcanic shards. The base of the tephra unit is always sharp but visual inspection and other measurements (carbonate and total organic carbon weight %) indicate a more diffuse upper boundary associated with bioturbation and with sediment reworking. Off northwest Iceland the Saksunarvatn tephra has distinct sediment magnetic properties. This is evident as a dramatic reduction in magnetic susceptibility, an increase in the frequency dependant magnetic susceptibility and ‘hard’ magnetisation in a −0.1T IRM backfield. Geochemical analyses from 11 sites indicate a tholeiitic basalt composition, similar to the geochemistry of a tephra found in the Greenland ice‐core that dates to 10 180 ± 60 cal. yr BP, and which was correlated with the 9000 14C yr BP Saksunarvatn tephra. We present accelerator mass spectrometry 14C dates from the marine sites, which indicate that the ocean reservoir correction is close to ca. 400 yr at 9000 14C yr BP off northwest Iceland. Copyright © 2002 John Wiley & Sons, Ltd.
The Loch Lomond Readvance on the Isle of Mull, Scotland: glacier reconstruction and palaeoclimatic implications
Authors: Ballantyne Colin K. 
Published: December 2002

AbstractGeomorphological mapping of Mull provides evidence for an icefield 143 km2 in area flanked by six corrie glaciers with a total area of ca. 13 km2. The absence of Lateglacial periglacial features, shorelines and pollen sites from the area occupied by this readvance, together with radiocarbon dating of shell fragments, confirm that it occurred during the Loch Lomond (Younger Dryas) Stade. The thickness of glacigenic deposits within the area of the readvance is attributed to reworking of paraglacial sediments. Up‐valley continuity of recessional moraines indicates that the ice remained active and near to equilibrium during retreat, consistent with slow warming following the coldest part of the stade. Reconstructed equilibrium line altitudes (ELAs) imply vigorous snow‐blowing by westerly winds, and are consistent with a general southwestwards decline in ELAs across the Scottish Highlands. An ELA of 250 m was calculated for the Mull Icefield using an ablation:accumulation balance ratio (ABR) approach. Palaeotemperature and palaeoprecipitation estimates were derived by calculating a theoretical regional ELA from meteorological data and assuming that the combination of temperature and precipitation implied by the theoretical ELA approximates conditions at 250 m on Mull during the Loch Lomond Stade. The result indicates a mean July sea‐level temperature of 5.7 ± 0.5°C and a mean annual precipitation at 250 m of ca. 2700–3800 mm (best estimate 3200 mm), indicating higher precipitation totals than at present owing to more vigorous atmospheric circulation. Copyright © 2002 John Wiley & Sons, Ltd.
Cascaded coherent Stokes Raman scattering in LiNbO3:Mg crystals under excitation of small polarons and phonon polaritons
Authors: Kitaeva G. Kh. , Kuznetsov K. A. , Penin A. N. , Solosin S. V. 
Published: December 2002

AbstractDispersion of the real ε′(ν) and the imaginary ε″(ν) parts of the dielectric function was measured by means of cascaded coherent Stokes Raman scattering (CSRS), in the spectral region of phonon polaritons 520–560 cm−1, for single crystals of LiNbO3:Mg, before and after chemical reduction of the samples. Comparison with the results obtained by spontaneous near‐forward Raman scattering showed that the excitation of polaritons under CSRS does not cause any changes in the dielectric function of the unreduced crystal. After the reduction, which leads to the formation of localized charge carriers, small polarons, we found a sufficient increase in the dielectric function imaginary part, measured by CSRS. This reduction‐induced increase reaches its maximum values in the region of Fermi resonance between polariton and biphonon states. The possible origin of this effect, connected with the enhancement of the lattice intermolecular anharmonicity under polaron hopping, is discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Kinetics and mechanism of decomposition of intermediate complex during oxidation of pectate polysaccharide by potassium permanganate in alkaline solutions
Authors: Khairou Khalid S. 
Published: December 2002

AbstractThe kinetics of decomposition of an [Pect·MnVIO42−] intermediate complex have been investigated spectrophotometrically at various temperatures of 15–30°C and a constant ionic strength of 0.1 mol dm−3. The decomposition reaction was found to be first‐order in the intermediate concentration. The results showed that the rate of reaction was base‐catalyzed. The kinetic parameters have been evaluated and found to be ΔS≠ = − 190.06 ± 9.84 J mol−1 K−1, ΔH≠ = 19.75 ± 0.57 kJ mol−1, and ΔG≠ = 76.39 ± 3.50 kJ mol−1, respectively. A reaction mechanism consistent with the results is discussed. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 67–72, 2003
Study of the reaction methyl 4‐nitrobenzene‐sulfonate + Cl− in mixed hexadecyltrimethyl‐ammonium chloride‐triton X‐100 micellar solutions
Authors: Fernández Gaspar , Rodríguez Amalia , Graciani María del Mar , Muñoz María , Moyá María Luisa 
Published: December 2002

AbstractThe reaction methyl 4‐nitrobenzenesulfonate + Cl− was studied in hexadecyltrimethylammonium chloride (CTAC) in the absence and presence of 0.1 M NaCl, as well as in mixed CTAC/Triton X‐100 (polyoxyethylene(9.5)octylphenyl ether) aqueous micellar solutions with CTAC molar fractions of 0.9, 0.8, 0.7, and 0.6. Conductivity measurements were used to obtain critical micellar concentrations and micellar ionization degrees of the various micellar reaction media. From these data, thermodynamic information on the cationic/nonionic mixed micellar solutions was obtained. Micellar effects on the observed rate constant were explained by pseudophase kinetic models. The estimated second‐order rate constants in the micellar pseudophase of the different micellar reaction media showed that pure CTAC and mixed CTAC/Triton X‐100 micelles, at the high cationic surfactant molar fractions studied, provide reaction sites of similar characteristics at the interfacial region. This was in agreement with previous structural studies carried out on mixed CTAC/Triton X‐100 micellar solutions. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 45–51, 2003
Theoretical studies on the mechanism and kinetics of the reaction of F atom with NCO radical
Authors: Zhou Zheng‐Yu , Guo Li , Gao Hong‐Wei 
Published: December 2002

AbstractThe reaction of a F atom with an NCO radical was studied at 6‐311+g* level, using DFT methods. All geometries, vibrational frequencies, and energies of different stationary points were calculated by HF, UMP2, and DFT methods, and the results agreed with the experimental values. The vibrational frequencies and vibrational modes of the reactant, intermediates, transition states, and products were calculated and the changes of these frequencies and modes were analyzed. Simultaneously, the vibrational modes of various species were assigned. The relationship and the change among these confirmed the mechanism of the reaction and the process of electron transfer. The major channel for the reaction was found to be the cis‐channel. At the same time the rate constant was estimated. A new method of analyzing reaction mechanism is also presented. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 52–60, 2003