bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in the ribosomal ITS-sequence of the lichens Buellia Frigida and Xanthoria Elegans from the Vestfold Hills, Eastern Antarctica
Authors: Dyer P. S. , Murtagh G. J. 
Published: September 2002

AbstractThalli of the lichens Buellia frigida and Xanthoria elegans were collected from five different locations each 5-15 km apart in the Vestfold Hills, Princess Elizabeth Land, eastern Antarctica. A further collection was made from Mawson Station, Mac Robertson Land, eastern Antarctica, 660 km away. DNA was extracted from whole thalli and the ribosomal ITS region amplified by PCR using fungal specific primers. Resulting products were sequenced to gain an indication of whether or not variation was present within populations of lichen-forming fungi from continental Antarctica, and therefore of the availability of genetic resources to react to pressures such as climate change. Three genotypes of B. frigida and two of X. elegans were detected in the Vestfold Hill collections. However, these differed by only one nucleotide position suggesting the presence of relatively little genetic variation, if the ITS region is indicative of the overall genome. Buellia frigida collected from Mawson Station had an identical ITS region sequence to the most common Vestfold Hills genotype, indicating that this species may have a low level of genetic variation across much of eastern Antarctica. In contrast, X. elegans collected from Mawson showed considerable genetic variation from the Vestfolds thalli, differing at 14·2% of nucleotide positions and had an identical ITS region sequence to an isolate from maritime Antarctica 4960 km away. Samples from the Vestfold Hills formed a distinct cluster in a phylogenetic analysis of ITS sequences from a worldwide collection of X. elegans isolates.
The lichen vegetation associated with areas of late snow-lie in the Scottish Highlands
Authors: Fryday Alan M. 
Published: September 2002

AbstractThe lichen vegetation associated with areas of late snow-lie in the Scottish Highlands is described and three lichen-dominated communities recognized; from the tops of large boulders, from small pebbles, and from damp soil. The first of these is exclusive to this habitat throughout the Highlands, whereas the other two are restricted to areas of late snow-lie in the Eastern Highlands but are of more widespread occurrence further west. The community from damp soil has affinities with the Solorinion croceae Klement, which occupies a similar ecological niche in Central Europe, but the two other communities are apparently undescribed. The importance of the eu-oceanic climate of the Western Highlands in determining the distribution of these communities is emphasized. The new combination Micarea cinerea f. tenuispora (D. Hawksw. & Poelt) Fryday is made for the anamorph of M. cinerea (Schaer.) Hedl.
Further records of foliicolous lichens and lichenicolous fungi from Australasia, with an updated checklist for continental Australia
Authors: Lücking Robert , Streimann Heinar , Elix John A. 
Published: September 2002

AbstractBased on collections gathered by H. Streimann and J. A. Elix in Papua New Guinea, Australia (including Tasmania), and Vanuatu, five new foliicolous lichen species are described: Calenia bullatinoides Lücking, Eremothecella cyaneoides Lücking, Fellhanera tasmanica Lücking & Elix, Fellhaneropsis australiana Lücking, and Porina vanuatuensis Lücking. In addition, the following new combinations are proposed: Coenogonium isidiiferum (Lücking) Lücking [Bas.: Dimerella isidiifera Lücking], Coenogonium lisowskii (Vězda) Lücking [Bas.: Dimerella lisowskii Vězda], Coenogonium queenslandicum (Kalb & Vězda) Lücking [Bas.: Dimerella queenslandica Kalb & Vězda], Echinoplaca tetrapla (Zahlbr.) Lücking [Bas.: Gonolecania tetrapla Zahlbr.], and Porina subepiphylla var. australiensis (Lücking & Vězda) Lücking [Bas.: Porina lucida var. australiensis Lücking & Vězda]. Coenogonium piliferum (Vězda) Kalb & Lěcking [Bas.: Dimerella pilifera Vě zda] is placed into synonymy with Coenogonium epiphyllum Vain. An updated checklist of foliicolous lichens from Australia includes 202 species and excludes five previously reported taxa.
Fellhanera gyrophorica, a new European species with conspicuous pycnidia
Authors: Sérusiaux E. , Coppins B. J. , Diederich P. , Scheidegger C. 
Published: September 2002

AbstractFellhanera gyrophorica Sérus., Coppins, Diederich & Scheidegger is described as new from Europe Austria, Lithuania, Luxembourg, Poland, Switzerland and Ukraine. It is a sterile corticolous species with conspicuous and sometimes shortly stalked pycnidia whose outer walls produce gyrophoric acid. Its position in the genus Fellhanera (Pilocarpaceae) is tentative and further studies may necessitate its transfer to another genus.
Parmeliopsis ambigua and P. hyperopta (Parmeliaceae): species or chemotypes?
Authors: Tehler Anders , Källersjö Mari 
Published: September 2002

AbstractITSl and ITS2 regions were sequenced from a number of Parmeliopsis ambigua and P. hyperopta specimens from Uppland, Sweden. The data were analysed cladistically and the ITS region was found to contain enough variation to support the hypothesis that the taxa should be regarded as species rather than chemotypes.
Gelatinopsis roccellae (Leotiales, Ascomycota), a new lichenicolous fungus on Roccella from NW Spain
Authors: Etayo Javier , Paz-Bermúdez Graciela , Diederich Paul 
Published: September 2002

AbstractThe new lichenicolous fungus Gelatinopsis roccellae is described from NW Spain, where it grows on Roccella fuciformis and R. phycopsis. It differs from G. ericewrum, which grows on Dibaeis, by the shorter ascospores, smaller ascomata, and the absence of an olivaceous excipular and epihymenial pigment.
Genetic Variability and its Geographical Distribution in the Widely Disjunct Cavernularia Hultenii
Authors: Printzen C. , Ekman S. 
Published: September 2002

AbstractThe fruticose lichen Cavernularia hultenii exhibits a strongly disjunct distribution between north-western North America, Newfoundland and north-western Europe. An investigation of its population structure, based on nuclear ITS and IGS DNA sequences, shows that western North America has a higher number of haplotypes than the two other areas. Most of the haplotypes confined to this region are rare and occur outside the area that was affected by Pleistocene glaciations. Three haplotypes are common in all three areas. The high number of haplotypes in western North America might be due to a combination of events during the Pleistocene and Holocene epochs, viz. increased lineage survival by repeated fragmentation of populations and reduced lineage extinction through rapid postglacial expansion and population growth.
Implications of the Radiocarbon Timescale for Ice-Sheet Chronology and Sea-Level Change
Authors: Tushingham A. Mark , Peltier W. Richard 
Published: September 2002

AbstractA new extended radiocarbon calibration curve has allowed a reexamination of relative sea-level data based on pre-Holocene dates. At sites located far from any Late Pleistocene ice sheet, the effect of employing this new calibration curve is that the calibrated data (with ages up to 17,100 14C yr B.P.) now agree with the corresponding relative sea-level curve predicted by the ICE-3G deglaciation model. An important implication of this new calibration curve is that the last glacial maximum (ca. 18,000 14C yr B.P.) is inferred to have occurred 22,000-21,000 cal yr B.P. This allows for additional ice to be incorporated in a revised deglaciation model than suggested by ICE-3G. The predicted relative sealevel curves of this new model match the relative sea-level data as well as those of ICE-3G. Further, the total sea-level rise of 124 m at Barbados since the last glacial maximum predicted by this new model agrees with the estimated value of 121 ± 5 m obtained from the depths of drowned reef-crest corals.
Wisconsinan Pre-Pleniglacial Biotic Change in Southeastern New Mexico
Authors: Harris Arthur H. 
Published: September 2002

AbstractInterpretation of a 1.5-m mid- to late- Wisconsinan stratigraphic sequence containing fossil vertebrates from the Animal Fair Site in Dry Cave, Eddy County, New Mexico, suggests a progression of habitats, all cooler and moister than today. Mid-Wisconsinan semiarid, moderately warm grasslands or grassy woodlands initially were replaced by cooler, more mesic, grassy woodlands; these were followed by cool, relatively dense sagebrush-grassland-woodland with elements from mixed-coniferous forest. A minor reversal of trend toward earlier, warmer conditions appears at the top of the section. Species collected from each level were basically harmonious until climatic deterioration, documented by invasion of new biotic elements at the end of the mid-Wisconsinan, permitted incursion of taxa associated with more boreal areas; these replaced most of the local fauna but failed to dislodge several taxa with southern affinities.
Rainfall Reconstruction Using Wood Charcoal from Two Archaeological Sites in South Africa
Authors: February ED C. 
Published: September 2002

AbstractMajor components of most southern African archaeological sites are stone, bone, and charcoal. A new technique for climate reconstruction utilizes measurements of vessel size and frequency in the cross-sectional xylem anatomy of archaeological charcoal from Collingham Shelter and Mhlwazini Cave in the Natal Drakensberg. Previous wood anatomical studies have shown that links exist among vessel diameter, vessel frequency and climate. The present study demonstrates that in relation to rainfall, vessel diameter in the speciesProtea caffraandProtea roupelliae correlated positively, whereas vessel frequency correlated negatively. InP. roupelliae, mean vessel diameter increases from 46 to 62 μm along a rainfall gradient ranging from 760 to 1665 mm. The significant correlations between rainfall and tangential vessel diameter for a charred sample ofP. roupelliaesuggest that such measures on an archaeological charcoal sample may be used to reconstruct rainfall patterns through time. Using nine assemblages of archaeological charcoal, generalized patterns of wetter and drier periods can be postulated. Comparison with contemporary values indicates that at 200 and 2400 yr B.P. the area near the archaeological sites was wetter than at present. A dry phase occurred between 1300 and 300 yr B.P. Values for the contemporary wood sample are the lowest observed, indicating that present conditions are much drier than those at any time within the last ca. 2000 yr. Dating resolution however, is insufficient to allow more-detailed interpretation of rainfall conditions over the past 2000 yr.
Dendroclimatic Reconstruction of Summer Temperatures in Northwestern Canada since A.D. 1638 Based on Age-Dependent Modeling
Authors: Szeicz Julian M. , MacDonald Glen M. 
Published: September 2002

AbstractRing widths from five Picea glauca stands at the alpine treeline in northwestern Canada are used to investigate climate-growth responses and to develop a long reconstruction of summer temperatures. Response function and linear regression analyses indicate that the radial growth response of these trees to climate varies with age and site. At most sites, the period of significant positive response to growing season temperatures declines with tree age. Age-dependent and standard (age independent) models are then used to develop two reconstructions of June-July temperatures for northwestern Canada extending back to A.D. 1638. Calibration statistics were similar for both models, but the standard model performed poorly during verification. The reconstruction produced using age-dependent modeling suggests June-July temperatures were cooler than present throughout most of the past 350 years, with the exception of the late 18th century. Particularly cool periods occurred at ∼1700 and in the mid-19th century. In constast, the standard model suggests that temperatures were similar to or warmer than present during the last 350 years. The age-dependent reconstruction compares favorably with other proxy climate records from northern North America. Age-dependent dendroclimatic modeling can provide a sensitive record of recent climatic change that allows the inclusion of previously rejected sites into dendroclimatic analyses.
Late-Holocene Formation of Lake Michigan Beach Ridges Correlated with a 70-yr Oscillation in Global Climate
Authors: Delcourt Paul A. , Petty William H. , Delcourt Hazel R. 
Published: September 2002

AbstractA radiocarbon-dated series of 75 beach ridges, formed at regular intervals averaging 72 yr over the past 5400 yr, provides further support for the existence of a 70-yr oscillation in Northern Hemisphere climate, postulated recently from instrument data representing less than two cycles of this climate oscillation. Results from this study lend support to the interpretation that internal variations in the ocean–atmosphere system are an important factor in climate fluctuations on a decadal–centennial time scale. A temperature oscillation with a period of about 70 yr has been a previously unrecognized but fundamental part of the global climate system since at least the middle Holocene.
Holocene Paleohydrology of the Tropical Andes from Lake Records
Authors: Abbott Mark B. , Seltzer Geoffrey O. , Kelts Kerry R. , Southon John 
Published: September 2002

AbstractTwo century-scale time series in northern Bolivia constrain the ages of abrupt changes in the physical, geochemical, and biological characteristics of sediments obtained from lakes that formed during deglaciation from the late Pleistocene glacial maximum. The watersheds of Laguna Viscachani (16°12′S, 68°07′W, 3780 m) and Lago Taypi Chaka Kkota (16°13′S, 68°21′W, 4300 m), located on the eastern and western slopes of the Cordillera Real, respectively, contain small cirque glaciers. A high-resolution chronology of the lake sediments is provided by 23 AMS14C dates of discrete macrofossils. Late Pleistocene glaciers retreated rapidly, exposing the lake basins between 10,700 and 970014C yr B.P. The sedimentary facies suggest that after 890014C yr B.P. glaciers were absent from the watersheds and remained so during the middle Holocene. An increase in the precipitation–evaporation balance is indicated above unconformities dated to ∼230014C yr B.P. in both Lago Taypi Chaka Kkota and Laguna Viscachani. An abrupt increase in sediment accumulation rates after 140014C yr B.P. signals the onset of Neoglaciation. A possible link exists between the observed millennial-scale shifts in the regional precipitation–evaporation balance and seasonal shifts in tropical insolation.
Multivariate Analysis of Remains of Molluscan Foods Consumed by Latest Pleistocene and Holocene Humans in Nerja Cave, Málaga, Spain
Authors: Serrano Francisco , Guerra-Merchán Antonio , Lozano-Francisco Carmen , Vera-Peláez José Luis 
Published: September 2002

AbstractNerja Cave is a karstic cavity used by humans from Late Paleolithic to post-Chalcolithic times. Remains of molluscan foods in the uppermost Pleistocene and Holocene sediments were studied with cluster analysis and principal components analysis, in bothQ and R modes. The results from cluster analysis distinguished interval groups mainly in accordance with chronology and distinguished assemblages of species mainly according to habitat. Significant changes in the shellfish diet through time were revealed. In the Late Magdalenian, most molluscs consumed consisted of pulmonate gastropods and species from sandy sea bottoms. The Epipaleolithic diet was more varied and included species from rocky shorelines. From the Neolithic onward most molluscs consumed were from rocky shorelines. From the principal components analysis inQ mode, the first factor reflected mainly changes in the predominant capture environment, probably because of major paleogeographic changes. The second factor may reflect selective capture along rocky coastlines during certain times. The third factor correlated well with the sea-surface temperature curve in the western Mediterranean (Alboran Sea) during the late Quaternary.
The Last Interglacial to Glacial Transition, Togiak Bay, Southwestern Alaska
Authors: Kaufman Darrell S. , Manley William F. , Wolfe Alexander P. , Hu Feng Sheng , Preece Shari J. , Westgate John A. , Forman Steve L. 
Published: September 2002

AbstractAn 18-m-high coastal bluff at Togiak Bay (northwestern Bristol Bay, southwestern Alaska) exposes marine, lacustrine, fluvial, glacial, volcanic, and organic deposits that record the ∼50,000-year-long transition from the peak of the last interglaciation to the early Wisconsin glaciation. The base of the section is dominated by stratified sand and silt extending up to 4.3 m above sea level; marine diatoms are present, and pollen assemblages are characterized by relatively high percentages of Picea, Alnus, and Betula and low percentages of Poaceae and Cyperaceae. The marine sediment was probably deposited during the peak of marine oxygen-isotope stage (OIS) 5e. An infrared stimulated luminescence (IRSL) age of 151,000±13,000 yr from near the base of the exposure is permissive of this correlation. The marine sand and silt are overlain by 0.8 m of peaty silt with diatoms that record a transition from marine to lacustrine conditions. During this interval, Poaceae and Cyperaceae dominate the pollen assemblages, and Picea and shrubs are nearly absent, suggesting that herb tundra occupied the landscape. This interval probably encompasses OIS 5d on the basis of the herb tundra and an IRSL age of 119,000±10,000 yr from 60 cm below the marine/lacustrine transition. The organic mud is overlain by 3.1 m of stratified sand and organic silt that apparently record shallowing of the lake; reappearance of spruce and shrubs (=OIS 5c?); and subsequent deepening of the lake (=OIS 5b?); followed by aggradation of a floodplain (=OIS 5a?), which was dry at the time basaltic lava buried the site. Thermoluminescence analyses on lava-baked sediment indicate that the eruption occurred 70,000±10,000 yr ago. Sometime thereafter, but prior to 53,600 14C yr B.P. an outlet of the Ahklun Mountains ice cap advanced over the site and deposited ∼7 m of bouldery ice-contact drift. The sedimentary sequence contains at least four tephra beds. Major- and trace-element chemistry provide a basis for correlating two of the tephras with tephra beds at nearby sites. The tephras, luminescence ages, and correlations with marine isotope stages provide the geochronological control to place the Togiak Bay section into a global context. The site serves as an important new reference section for late Pleistocene paleoenvironmental change in eastern Beringia.
Fluctuations in Terrestrial–Marine Environments in the Western Equatorial Pacific during the Late Pleistocene
Authors: Kawahata Hodaka , Maeda Rena , Ohshima Hideaki 
Published: September 2002

AbstractLarge heat storage capacity in the western equatorial Pacific has played an important role in modulating global climate. The fluctuation in pollen and spore abundances, together with organic matter (OM) and lithogenics sedimentation, was investigated to reconstruct terrestrial and marine environmental change around New Guinea during the Late Pleistocene. Although appreciable contribution from Indonesian Maritime Continent was expected, the majority of the pollen and spore grains found in core C4402 was transported from New Guinea. Fern spores accounted for 70% (46–90%) of the total pollens and spores. Positive correlation between lithogenic content and the relative abundance of fern spores suggests that lithogenics could be derived from coastal lowland.The mass accumulation rate (MAR) of pollen and spores varied from 44 to 7,031×10−3 grains cm−2 yr−1 with maxima in oxygen isotope stages (OIS) 2, 3, 4, and around the OIS 4/5 boundary. Less rainfall during glacial times generally enhanced transport of pollen by wind to Site C4402. Their scavenging from the water column was promoted by high activity of the biological pump. Pollen record from core C4402 suggests that lower montane group vegetation was dominant relative to lowland vegetation and upper and mid-montane group during glacial times. Although appreciable contribution by terrestrial OM is expected from high correlation of MAR between organic carbon (OC) and pollen and spores, fairly low COrganic/N ratios and δ13C values (around −20‰) of OM demonstrate that OM in core C4402 is mainly of marine origin.
Late Pleistocene Glaciations in the Northwestern Sierra Nevada, California
Authors: James L. Allan , Harbor Jon , Fabel Derek , Dahms Dennis , Elmore David 
Published: September 2002

AbstractPleistocene fluvial landforms and riparian ecosystems in central California responded to climate changes in the Sierra Nevada, yet the glacial history of the western Sierra remains largely unknown. Three glacial stages in the northwestern Sierra Nevada are documented by field mapping and cosmogenic radionuclide surface-exposure (CRSE) ages. Two CRSE ages of erratic boulders on an isolated till above Bear Valley provide a limiting minimum age of 76,400±3800 10Be yr. Another boulder age provides a limiting minimum age of 48,800±3200 10Be yr for a broad-crested moraine ridge within Bear Valley. Three CRSE ages producing an average age of 18,600±1180 yr were drawn from two boulders near a sharp-crested bouldery lateral moraine that represents an extensive Tioga glaciation in Bear Valley. Nine CRSE ages from striated bedrock along a steep valley transect average 14,100±1500 yr and suggest rapid late-glacial ice retreat from lower Fordyce Canyon with no subsequent extensive glaciations. These ages are generally consistent with glacial and pluvial records in east-central California and Nevada.
Endothelin‐1‐induced venous contraction is maintained in DOCA‐salt hypertension; studies with receptor agonists
Authors: Watts Stephanie W , Fink Gregory D , Northcott Carrie A , Galligan James J 
Published: September 2002

Deoxycorticosterone acetate (DOCA) salt hypertension is associated with an endothelin‐1 (ET‐1)‐dependent increase in arterial resistance and mean circulatory filling pressure. Contraction of endothelium‐intact arteries and veins from sham and DOCA‐salt hypertensive rats to agonists of the ETA (ET‐1(1–31)) and ETB receptor (sarafotoxin 6c; S6c) was investigated in tissue baths as was expression of mRNA for ET‐1 and mRNA and protein for the ETA and ETB receptor.
ET‐1(1–31) contracted aorta and vena cava from sham rats with a 30 fold lower potency than ET‐1. Contraction was not altered by the ETB receptor antagonist BQ788 (100 nM) but was abolished by the ETA receptor antagonist ABT‐627 (30 nM).
In DOCA‐salt thoracic aorta, maximum contraction to ET‐1 and ET‐1(1–31) was reduced (36.6±6.3 and 13.3±4.4% of sham response, respectively); aorta did not contract to S6c.
In vena cava from DOCA‐salt rats, contraction to ET‐1 and ET‐1(1–31) was not reduced compared to sham contraction; vena cava from sham and DOCA‐salt rats contracted to S6c with a similar potency.
Real time RT–PCR revealed that prepro ET‐1 mRNA was increased 6.6±3.3 fold and 8.7±3.9 fold greater in DOCA‐salt aorta and vena cava, respectively, compared to sham. Vena cava expressed a higher content of ETA and ETB receptor mRNA than aorta (P<0.05), but no differences were observed between sham and DOCA‐salt tissues. ETA and ETB receptor protein was identified in all tissues. Immunoreactive ETA receptor, observed as a 65, 30 and 28 kDa bands, was expressed 400% greater in DOCA‐salt aorta compared to sham, but was not altered in vena cava. Immunoreactive ETB receptor, observed as 120, 45 and 30 kDa bands, tended to be higher in vena cava compared to aorta, but was not different in sham and DOCA‐salt vena cava.
These results suggest that ETA receptor function is impaired in aorta but not vena cava of DOCA‐salt rats. The ETB receptor was present in the aorta but, unlike in veins, does not mediate contraction directly. A sustained response to ET‐1 in the venous circulation may contribute to the elevated blood pressure in the DOCA‐salt model.

British Journal of Pharmacology (2002) 137, 69–79. doi:10.1038/sj.bjp.0704831