bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation of Late Pleistocene Glaciolacustrine and Marine Deposits by Means of Geomagnetic Secular Variation, with Examples from Northern New York and Southern Ontario
Authors: Pair Donald L. , Muller Ernest H. , Plumley Peter W. 
Published: October 2002

AbstractThe geomagnetic secular variation record retained by glaciolacustrine and marine sediments at nine sites in northern New York and southern Ontario provides a means for stratigraphic correlation of glacial deposits for the time period between about 12,600 to 9900 14C yr B.P. Measurement of the depositional remanent magnetism of sediments deposited in Glacial Lake Iroquois and the Champlain Sea has produced a geomagnetic secular variation curve that represents the time period immediately following deglaciation about 12,600 14 C yr B.P. The curve varies from about 358° to 344° declination and 51° to 61° inclination over approximately 180 valve years. Marine sediments of the Champlain Sea have preserved a record approximately 1500 yr long that varies from about 2° to 29° declination and 47° to 60° inclination. These combined glacial-paleomagnetic records may also correlate with those from glacial sequences beyond our study area. The shape and amplitude of the secular variation record in glaciolacustrine and marine sediments from the western Adirondack borderland show agreement with other glacial varve secular variation records and suggest possible correlations with secular variation curves from lake cores.
Numerical Modeling of the Late Weichselian Svalbard-Barents Sea Ice Sheet
Authors: Siegert Martin J. , Dowdeswell Julian A. 
Published: October 2002

AbstractPrevious reconstructions of the ice cover of the Svalbard-Barents Sea region during the late Weichselian have ranged from small ice masses on Svalbard to complete inundation of the Barents Shelf region by an ice sheet several kilometers thick. We have used a time-dependent finite-difference numerical model to undertake a new glaciological reconstruction for the Svalbard-Barents Sea Ice Sheet over the last 30,000 yr. The numerical model requires environmental forcing functions in the form of air temperature and precipitation and their behavior with respect to altitude, together with sea-level change and an iceberg calving relation. Ice buildup on Svalbard is calculated to have begun 28,000 yr ago, and maximum dimensions were reached by 20,000 yr ago, covering Svalbard and the northwestern Barents Sea with a center of mass (1.3 km thick) around eastern Svalbard. Decay was complete by about 10,000 yr ago. The margin of the modeled ice sheet at its maximum is in good agreement with observed sea-floor morphological features, but there are discrepancies in timing between the modeled ice sheet decay and (i) a dated meltwater spike in Fram Strait and (ii) the observed rebound curves for Svalbard. An inverse approach was used to predict ice sheet decay, and it was found that increasing the rate of iceberg calving within the model produces a deglaciation some 2000 yr earlier, which is compatible with these two independent datasets. The reconstruction is also compatible with geological evidence on the isostatic response of Bjørnøya, close to the southern limit of the ice sheet, and seismically observed deposits, interpreted to be ice. proximal facies, located in the northwestern Barents Sea. Our time-dependent model reconstructions of the Svalbard-Barents Sea Ice Sheet indicate ice cover over only the northwestern Barents Sea during the late Weichselian, but this does not preclude the presence of ice derived from Fennoscandia and the Kara Sea region elsewhere in the Barents Sea.
Do Greenland Ice Cores Reflect NW European Interglacial Climate Variations?
Authors: Larsen Eiliv , Sejrup Hans Petter , Johnsen Sigfus J. , Knudsen Karen Luise 
Published: October 2002

AbstractThe climatic evolution during the Eemian and the Holocene in western Europe is compared with the sea-surface conditions in the Norwegian Sea and with the oxygen-isotope-derived paleotemperature signal in the GRIP and Renland ice cores from Greenland. The records show a warm phase (ca. 3000 yr long) early in the Eemian (substage 5e). This suggests that the Greenland ice sheet, in general, recorded the climate in the region during this time. Rapid fluctuations during late stage 6 and late substage 5e in the GRIP ice core apparently are not recorded in the climatic proxies from western Europe and the Norwegian Sea. This may be due to low resolution in the terrestrial and marine records and/or long response time of the biotic changes. The early Holocene climatic optimum recorded in the terrestrial and marine records in the Norwegian Sea-NW European region is not found in the Summit (GRIP and GISP2) ice cores. However, this warm phase is recorded in the Renland ice core. Due to the proximity of Renland to the Norwegian Sea, this area is probably more influenced by changes in polar front positions which may partly explain this discrepancy. A reduction in the elevation at Summit during the Holocene may, however, be just as important. The high-amplitude shifts during substage 5e in the GRIP core could be due to Atlantic water oscillating closer to, and also reaching, the coast of East Greenland. During the Holocene, Atlantic water was generally located farther east in the Norwegian Sea than during the Eemian.
AMS 14C Dates for Extinct Lemurs from Caves in the Ankarana Massif, Northern Madagascar
Authors: Simons Elwyn L. , Burney David A. , Chatrath Prithijit S. , Godfrey Laurie R. , Jungers William L. , Rakotosamimanana Berthe 
Published: October 2002

AbstractAn extensive late Quaternary fauna, including many extinct giant lemurs, has been collected recently in a 110+-km system of caves in the Ankarana Massif of northern Madagascar. AMS 14C dates for the acid-insoluble (collagen/gelatin) fraction of bones of the giant lemur Megaladapis (26,150 ± 400 and 12,760 ± 70 yr B.P.) confirm its presence in the area during the late Pleistocene and provide the first Pleistocene 14 C ages from bones of the extinct megafauna of the island. The first date from bones of the recently described extinct Babakotia radofilai (4400 ± 60 yr B.P.) shows that it was present in northern Madagascar in mid-Holocene times. A comparatively recent age of 1020 ± 50 yr B.P. for the extinct Archaeolemur indicates survival of this genus for at least a millennium after the first direct evidence for humans in Madagascar. This suggests that the island's "extinction window" may have represented a longer time span than would have been expected under the Blitzkrieg model of late Quaternary extinctions. A mid-Holocene age (4560 ± 70 yr B.P.) for a bone sample of the small extant lemur Hapalemur simus indicates that the disappearance of this now-restricted species from the Ankarana occurred after this date. New data from the Ankarana and other sites on the island add to the consensus that major biotic changes occurred on Madagascar in the late Holocene.
Grassland Vegetation in the Southern Great Plains during the Last Glacial Maximum
Authors: Hall Stephen A. , Valastro Salvatore 
Published: October 2002

AbstractNew pollen records from White Lake in the Southern High Plains and from Friesenhahn Cave on the southeastern Edwards Plateau of Texas indicate that the glacial-age vegetation of the southern Great Plains was a grassland. The High Plains was a treelessArtemisiagrassland and the Edwards Plateau, at the south edge of the Great Plains, was a grassland with pinyon pines and deciduous trees in canyons and riparian habitats. The glacial-age grasslands differ from modern shortgrass and tallgrass prairies and may have no modern analog. The dominance of prairie vegetation during the last glacial maximum is compatible with late Pleistocene mammalian faunas and late-glacial grassland pollen records from the region. Earlier interpretations of a pine-spruce forest on the High Plains were based on pollen assemblages that are here shown to have been altered by postdepositional deterioration, resulting in differential preservation of conifer pollen grains. Accordingly, the "Tahoka Pluvial" and other "climatic episodes" defined by High Plains pollen records are abandoned.
Sea Level Changes in the Last Several Thousand Years, Penghu Islands, Taiwan Strait
Authors: Chen Yue-Gau , Liu Tsung-Kwei 
Published: October 2002

AbstractHolocene shore-face and beach-face deposits form plains <5 m above present sea level along Taiwan Strait. We measured the 14C ages of detrital mollusk shells and coral in such deposits at the Penghu Islands. Twelve carbonate samples—mainly from the largest island, Makung—were dated. Age measurements for two coral samples and one mollusk sample from the same outcrop imply that the 14C ages of mollusk shells give the best approximation of depositional age. The highest Holocene relative sea level in the Penghu Islands occurred about 4700 years ago with a height about 2.4 m above the present sea level. Thereafter, relative sea level appreciably fell without detectable fluctuations to its recent position. Our sea level data are consistent with other studies from the central and western Pacific, except for the timing of peak sea level position. This variation may reflect local crustal response to hydroisostatic effects on the continental shelf.
Late Quaternary Temporal and Event Classifications, Great Lakes Region, North America
Authors: Johnson W. Hilton , Hansel Ardith K. , Bettis E. Arthur , Karrow Paul F. , Larson Grahame J. , Lowell Thomas V. , Schneider Allan F. 
Published: October 2002

AbstractSeveral temporal and event classifications are used for the Quaternary glacial and interglacial record in the Great Lakes region of North America. Although based on contrasting principles, the classifications, as practiced, are similar to one another in most respects and they differ little from the classification proposed by Chamberlin a century ago. All are based on stratigraphic units having time-transgressive boundaries; thus the associated time spans and events are diachronous. Where application of geochronologic classification based on isochronous boundaries is not practical or useful, we advocate the use of diachronic principles to establish local and regional temporal and event classifications. Diachronic and event classifications based on such principles are proposed herein for the Great Lakes region. Well-established names, including Wisconsin, Sangamon, and Illinois, are used at the episode (or glaciation/interglaciation) rank without significant redefinition. The Hudson Episode (Interglaciation) is introduced for postglacial time, the current interglacial interval. The Wisconsin Episode is divided into the Ontario, Elgin, and Michigan Subepisodes in the eastern and northern parts of the Great Lakes region and into the Athens and Michigan Subepisodes in the southern and western parts of the Great Lakes region.
Refinements of the European Mammal Biochronology from the Magnetic Polarity Record of the Plio–Pleistocene Zújar Section, Guadix-Baza Basin, SE Spain
Authors: Oms Oriol , Dinarès-Turell Jaume , Agustı́ Jordi , M. Parés Josep 
Published: October 2002

AbstractThe magnetobiostratigraphy study of the 130-m-thick Zújar section (Negratı́n clays unit, Guadix-Baza Basin, Spain) provides a remarkable opportunity to improve the correlation of European mammal biostratigraphy to the Geomagnetic Polarity Time Scale. The occurrence of 12 well-defined magnetozones and four paleontological sites with diagnostic faunas ranging from the MN 15 biozone (Ruscinian) to the MN 17 biozone (Villanyian), leads to an unambiguous correlation to chrons spanning from the Gilbert to the Matuyama epochs. This provides two new time constraints: (1) the boundary between MN 15 (Ruscinian) and MN 16 (Villanyian) biozones is recorded between chron C2An.3n and the base of chron C2An.2n and (2) the boundary between the upper and lower MN 16 subzones (Villanyian) is located between chron C2An.2n and the base of chron C2An.1n. The correlation between the Ruscinian–Villanyian boundary and the 3.3-myr-B.P. cooling event seems to be confirmed, while the early/late Villanyian boundary could be tentatively correlated to the glacial event at 2.6 myr B.P. Furthermore, MN 15 faunas are found in the lowermost part of chron C2Ar, which is in agreement with and reinforces the emplacement of the MN 14–MN 15 Ruscinian zones boundary at the reversal from chron 3n.1n to chron C2Ar.
Quaternary Stratigraphy and Paleogeography of the Galilee Coastal Plain, Israel
Authors: Sivan Dorit , Gvirtzman Gedaliahu , Sass Eytan 
Published: October 2002

AbstractThe Quaternary deposits in the Galilee coastal plain comprise alternating calcareous sandstone, red loam, dark clay, and uncemented sand. The calcareous sandstone in the lower part of the sequence represents a Pliocene to early Pleistocene marine transgression, and is covered unconformably by the late Quaternary sequence. The base of this sequence has an estimated age of ∼500,000 yr. It is covered unconformably by marine calcareous sandstone in the west, which represents the global high sea-level stand of isotope stage 7.1, and is known as one of the “Tyrrhenian” events in the Mediterranean area. The overlying members represent the low sea-level stand of stage 6, the first a red paleosol indicating a relatively wet phase and the second an eolianite unit representing a drier phase. The eolianite forms longitudinal, subparallel ridges that formed contemporaneously. The overlying marine sandstone, which contains one of the diagnostic fossils of the “Tyrrhenian” events, the gastropodStrombus buboniusLMK, accumulated during the global high stand of stage 5.5. The last glacial period left no sedimentary record. The Holocene is represented by a marine clay unit that is covered by sand. The present study establishes a complete and detailed chronostratigraphic sequence for an eastern Mediterranean beach, which contains the gastropodS. buboniusLMK.S. buboniuson the Galilee coast is attributed to stage 5.5 and therefore, establishes an east–west Mediterranean correlation, which can be used for linking Mediterranean events to paleo-sea levels and global climate changes.
Three‐dimensional reconstruction of biliary tract using spiral computed tomography for laparoscopic cholecystectomy
Authors: Ichii Hirohito , Takada Moriatsu , Kashiwagi Ryoichi , Sakane Masayoshi , Tabata Fumihira , Ku Yonson , Fujimori Takahiro , Kuroda Yoshikazu 
Published: October 2002

AbstractTo increase the safety of laparoscopic cholecystectomy, we have analyzed the biliary tract in a three‐dimensional fashion. The union of the biliary ducts was studied in 50 patients using spiral computed tomography (CT) after intravenous infusion cholangiography. Depending on the union and course of the cystic duct to the common bile duct, cystic duct anatomy was classified into six categories: ipsilateral gallbladder side (type I) and contralateral side with anterior course (type II); contralateral side with posterior course (type III); intrahepatic side (type IV); intrapancreatic side (type V); and unclassified (type VI). The length of the cystic duct was also determined. The cystic duct was identified in 42 cases (84%); 30 cases (60%) were type I, 9 cases (18%) type III, and a single case (2%) of types II, IV and V, respectively. The length of the cystic duct was ≥2 cm in 30 cases that had a shorter operating time compared to 12 cases with a cystic duct <2 cm (p<0.01). In conclusion, three‐dimensional reconstruction of the cystic duct anatomy using spiral CT provides simple classification of bile duct anatomy, and this preoperative information may increase the safety of laparoscopic cholecystectomy.
Normocalcemia and persistent elevated serum concentrations of 1–84 parathyroid hormone after operation for sporadic parathyroid adenoma: evidence of increased morbidity from cardiovascular disease
Authors: Vestergaard Henrik , Kristensen Lars Østergaard 
Published: October 2002

AbstractElevated serum concentrations of 1–84 parathyroid hormone (PTH) after operation for sporadic parathyroid adenoma have been re‐ported in previous studies, years after operation for primary hyperparathyroidism (pHPT). The cause and significance of this finding have not been elucidated. Primary hyperparathyroidism was diagnosed in 195 patients from January 1987 to December 1998. Operation for pHPT was performed in 124 patients. To evaluate long‐term effects of elevated serum 1–84 PTH, biochemical variables and pre‐ and postoperative diseases were investigated from hospital case records. Of the 124 patients operated on, 103 had a solitary adenoma. Among these patients, 60 had normal serum concentrations of 1–84 PTH and calcium postoperatively, 38 patients had follow‐up for more than 12 months (range 12–207 months—group A). Persistent elevated serum concentrations of 1–84 PTH and normocalcemia were found in 23 patients. Fourteen patients had follow‐up for more than 12 months (range 15–76 months—group B). Two patients had persistent pHPT, and 18 were normocalcemic, but in this retrospective study data on serum 1–84 PTH were not available. No significant differences were found between groups A and B at the time of diagnosis concerning clinical characteristics. More that 12 months after operation for pHPT, the patients in group B, with persistent elevated serum concentrations of 1–84 PTH, had a significantly (χ2=11, p=0.005, and power of test 0.66) higher frequency of cardiovascular diseases from ischémie heart disease and hypertension. Persistent elevated serum concentrations of 1–84 PTH after operation for sporadic parathyroid adenoma may be associated with development of cardiovascular disease. This group of patients therefore needs lifelong control and, possibly, medical intervention.
Surgical results in patients with hepatitis virus‐related hepatocellular carcinoma in Taiwan
Authors: Chen Miin‐Fu , Jeng Long‐Bin , Lee Wei‐Chen 
Published: October 2002

AbstractTo investigate the surgical results of hepatectomy for hepatocellular carcinoma in relation to hepatitis virus status in Taiwan, 252 patients (196 men and 56 women; March 1992 to August 1998) were reviewed. The patients were divided into four groups: 30 patients (11.9%) seronegative for both hepatitis B surface antigen (HBsAg) and antihepatitis C antibody (HCVAb) (N‐HCC group); 133 patients (52.8%) seropositive for HBsAg and seronegative for HCVAb (B‐HCC group); 66 patients (26.2%) seronegative for HBsAg and seropositive for HCVAb (C‐HCC group); and 23 patients (9.1%) seropositive for both HBsAg and HCVAb (BC‐HCC group). Patients in group C‐HCC were older (p=0.001) and had a higher incidence of diabetes mellitus (p=0.004). Also, they had a higher indocyanine green retention rate at 15 minutes (p=0.021), longer international normalization ratio for the prothrombin time (p=0.049), and smaller tumor (p=0.006). Postoperative complications and hospital mortality were significantly higher in patients in the C‐HCC and BC‐HCC groups (p=0.046, 0.021). All patients were followed 12 to 76 months after hepatectomy (mean 23.5±16.3 months). The 1‐, 3‐, and 5‐year overall cumulative survival rates of the 252 patients in this series were 80%, 54.3%, and 34.2%, respectively. The cumulative intrahepatic recurrence rates were 46.5%, 64.9%, and 72.9% at 1, 3, and 5 years, respectively. The mean disease‐free survival time was longest in group C‐HCC and shortest in group BC‐HCC (p=0.020). The overall survival time and cumulative survival rates in the four groups were not significantly different (p=0.146).
Metallothionein: Early marker in the carcinogenesis of ulcerative colitis‐associated colorectal carcinoma
Authors: Bruewer Matthias , Schmid Kurt W. , Krieglstein Christian F. , Senninger Norbert , Schuermann Guido 
Published: October 2002

AbstractMetallothioneins (MTs) are zinc‐binding proteins whose over‐expression may lead to sequestration of zinc ions and consequently to functional inactivation of the p53 tumor suppressor gene. The aim of the study was to investigate the potential role of MTs in the carcinogenesis of ulcerative colitis (UC) as well as possible effects on p53 function. The monoclonal antibodies E9 (anti‐MT), DO‐7, and 1801 (anti‐p53) and the polyclonal antibody CM‐1 (anti‐p53) were used to stain formalin‐fixed, paraffin‐embedded colon specimens obtained from 14 patients with UC‐associated colorectal carcinoma (CAC), 13 with high‐grade dysplasia (HGD), 10 with low‐grade dysplasia (LGD), and 30 with UC without dysplasia or carcinoma. Statistical significance (p<0.05) was assessed using Fisher’s exact test. Positive MT staining (>20% of tumor, dysplastic, or epithelial cells) was found in most UC and LGD but in only a small percentage of HGD and CAC (p<0.01 for CAC vs. UC and LGD vs. HGD). Positive p53 immunoreactivity was observed predominantly in HGD and CAC but not in LGD and UC (p<0.01 for CAC vs. UC and HGD vs. LGD). In histologically normal tissue neighboring CAC, significant MT expression was found in six of seven specimens with simultaneous lack of p53 expression. MT overexpression may represent an important early step in the development of CAC independent of p53 expression and should be investigated in the long term as an independent cancer risk factor in UC.
Pedestrian conspicuity at night: failure to observe a biological motion advantage in a high‐clutter environment
Authors: Moberly Nicholas James , Langham Martin Paul 
Published: October 2002

AbstractUsing recent accident data to simulate a common collision environment, a 10‐minute car journey was filmed in which a moving or stationary pedestrian wearing one of two types of retroreflective clothing appeared in an environment with high visual clutter. It was hypothesized that moving pedestrians would be detected at greater distances when wearing retroreflective aids in biological motion configuration (‘biomotion’ clothing), but not when wearing a standard retroreflective vest. Participants viewed films of the journey, pressed a button when they detected the pedestrian and rated the difficulty of the task. Biomotion clothing did not significantly increase detection distance for either moving or stationary pedestrians compared to the vest. However, moving pedestrians were detected significantly further away than stationary pedestrians with both clothings. The results do not support the hypothesis that biological motion clothing affords recognition at greater distances than standard conspicuity aids in environments with high visual clutter. Copyright © 2002 John Wiley & Sons, Ltd.
Mixed‐data multi‐modelling for fault detection and isolation
Authors: Kárný Miroslav , Nagy Ivan , Novovičová Jana 
Published: October 2002

AbstractEarly recognition/isolation of a faulty behaviour of a dynamic system is the main task of a fault detection and isolation (FDI). FDI methods based on adaptive probabilistic models with multiple modes represent a theoretically well justified way of solution. Their use is severely restricted by an inherent computational complexity.The complexity problem is addressed here by employing an efficient quasi‐Bayes estimation algorithm. It is directly applicable to the mixture of components created as products of factors belonging to the exponential family. It opens a novel way to deal adaptively with mixed continuous–discrete, dynamically related data. The presented theory and algorithmization are illustrated by a simple simulation example. Copyright © 2001 John Wiley & Sons, Ltd.
Adaptive control of continuous time stochastic systems
Authors: Duncan T.E. , Pasik‐Duncan B. 
Published: October 2002

AbstractSome problems and solutions of adaptive control problems for continuous time stochastic systems are described. A solution is given to the adaptive linear quadratic Gaussian control problem under the natural assumptions of controllability and observability. The effects of sampling and numerical differentiation on a least‐squares estimation algorithm are described. Adaptive control problems for non‐linear stochastic systems and linear stochastic distributed parameter systems are briefly described. Copyright © 2002 John Wiley & Sons, Ltd.