bluuebunny/crossref_metadata_2025_split huggingface dataset:
Urinary sugar phosphates and related organic acids in fructose‐1,6‐diphosphatase deficiency
Authors: Nakai A. , Shigematsu Y. , Liu Y. Y. , Kikawa Y. , Sudo M. 
Published: December 2004

SummaryTwo sisters with fructose‐1,6‐diphosphatase deficiency are reported. They presented with ketonuria, elevated plasma transaminase activity and severe metabolic acidosis during hypoglycaemic crises, which resembled Reye syndrome. Intravenous fructose tolerance tests provoked severe hypoglycaemia and metabolic acidosis. Fructose‐1,6‐diphosphatase activities in both peripheral leukocytes and cultured lymphocytes were below the limit of detection. Urinary organic acid analysis during crises revealed markedly increased excretion of lactate, ketone bodies, glycerol and glycerol‐3‐phosphate. We newly identified other glycolytic intermediates, glyceraldehyde, 3‐phosphoglycerate and fructose‐1,6‐diphosphate, in the urine during hypoglycaemic attacks or after fructose tolerance tests. Identification of such compounds may be useful in the early diagnosis of this disease.
Functional studies in fibroblasts of adenylosuccinase‐deficient children
Authors: Van den Bergh F. , Vincent M. F. , Jaeken J. , Van den Berghe G. 
Published: December 2004

SummaryIn fibroblasts of severely retarded (type I) adenylosuccinase (ASase)‐deficient children, activities with the two substrates of the enzyme, succinylaminoimidazole carboxamide ribotide (succinyl‐AICAR) and adenylosuccinate are decreased in parallel, to about 30% of normal. In a markedly less retarded (type II) patient, ASase activity with adenylosuccinate reaches only 3% of normal, whereas activity with succinyl‐AICAR is also about 30% of normal. To assess the functional significance of a partial versus a profound deficiency of ASase, precursor incorporation studies were performed in intact fibroblasts. In cells from controls and from type I patients, incorporation of 0.2 mmol/L [14C]formate into adenine and guanine nucleotides was not accompanied by accumulation of either [14C]succinyl‐AICAR or [14C]adenylosuccinate. Similarly, incorporation of 20 µmol/L [14C]hypoxanthine was not accompanied by accumulation of [14C]adenylosuccinate. In contrast, in fibroblasts of the type II patient, in accordance with the profound deficiency of ASase with adenylosuccinate, and with the inhibitory effect of Cl− and nucleotides on the activity with succinyl‐AICAR, incorporation of [14C]formate resulted in accumulation of [14C]succinyl‐AICAR and [14C]adenylosuccinate, and incorporation of [14C]hypoxanthine in a marked build‐up of [14C]adenylosuccinate. That both precursors were still incorporated into the adenine nucleotides of the fibroblasts of the type II patient indicates that adenylate synthesis remains possible even with 3% residual ASase activity, as also shown by their grossly normal ATP concentrations. The results suggest that the pathophysiology of ASase deficiency may be mediated at least in part by accumulation of succinyladenosine and succinyl‐AICAriboside.
A fluorimetric enzyme assay for the diagnosis of Sanfilippo disease C (MPS III C)
Authors: Voznyi Ya. V. , Karpova E. A. , Dudukina T. V. , Tsvetkova I. V. , Boer A. M. , Janse H. C. , van Diggelen O. P. 
Published: December 2004

SummaryBoth the α‐ and β‐anomers of 4‐methylumbelliferyl‐D‐glucosaminide were synthesized and shown to be substrates for the lysosomal acetyl‐CoA: glucosaminideN‐acetyltransferase. Using the β‐anomer, fibroblasts and leukocytes from 11 different Sanfilippo C patients showed <1% of mean normalN‐acetyltransferase activity. Heterozygotes showed intermediate activities. The enzymatic liberation of the fluorochrome from 4‐methylumbelliferyl‐β‐d‐glucosaminide requires the sequential action of theN‐acetyltransferase and β‐hexosaminidase. Normal β‐hexosaminidase activity caused complete hydrolysis of the reaction intermediate 4‐methylumbelliferyl‐β‐d‐N‐acetylglucosaminide formed by theN‐acetyltransferase. In cell extracts with a β‐hexosaminidase deficiency, however, a second incubation in the presence of excess β‐hexosaminidase is needed to avoid underestimation of theN‐acetyltransferase activity.
Nutritional value of essential amino acids in the treatment of adults with phenylketonuria
Authors: Dotremont H. , François B. , Diels M. , Gillis P. 
Published: December 2004

ConclusionThe present short‐term N‐balance study in adult PKU patients receiving a mixture of LNAA establishes a limited retention of nitrogen. Whether lysine could be the limiting amino acid remains to be determined by new short‐term N‐balance studies, with lysine added to the LNAA mixture. Therefore, special caution should be taken in the long‐term use in PKU patients of LNAA without any added lysine.
Acylcarnitine profile in tissues and body fluids of biotin‐deficient rats with and withoutl‐carnitine supplementation
Authors: Shigematsu Y. , Bykov I. L. , Liu Y. Y. , Nakai A. , Kikawa Y. , Sudo M. , Fujioka M. 
Published: December 2004

SummarySince biotin‐deficient (BD) rats are a good animal model for human multiple carboxylase deficiency and have low plasma free carnitine levels, short‐chain acylcarnitine profiles in biotin‐deficient rats withl‐carnitine supplementation (BDC rats) and BD rats were investigated by fast‐atom bombardment and tandem mass spectrometry and gas chromatography/mass spectrometry. By the latter method, 3‐hydroxyisovalerylcarnitine was identified in BD rats, and showed the greatest accumulation among short‐chain acylcarnitines in tissues of BD rats, while the tissue levels of propionic acid were more markedly elevated than those of 3‐hydroxyisovaleric acid. The tissue levels of 3‐hydroxyisovaleryl‐carnitine were significantly lower and those of propionyl‐carnitine were somewhat higher in BDC rats than in BD rats, while the tissue levels of propionic acid and 3‐hydroxyisovaleric acid in BDC rats were lower than those in BD rats. These changes were more apparent in kidney than in other tissues. The amounts of urinary excretion of acylcarnitines were markedly larger, and those of 3‐hydroxyisovaleric acid were somewhat smaller in BDC rats than in BD rats, while those of propionic acid were very low in BD and BDC rats as compared with those of 3‐hydroxyisovaleric acid. It seems that the relationship between the concentrations of 3‐hydroxyisovalerylcarnitine and those of propionylcarnitine reflects the unique metabolism of the related metabolites in tissues, especially in kidney, which may be influenced by their urinary excretion and the availability of free carnitine. These data in biotin deficiency suggest that carnitine supplementation is possibly beneficial for patients with holocarboxylase synthetase deficiency who respond incompletely to biotin therapy.
Late- and Postglacial Climatic Change in the Northern Midwest, USA: Quantitative Estimates Derived from Fossil Pollen Spectra by Multivariate Statistical Analysis
Authors: Webb Thompson , Bryson Reid A. 
Published: December 2004

Canonical correlation analysis provides a means of reconstructing quantitative time series of past climatic variables during the last 15,000 years from fossil pollen spectra collected at three sites in the northern Midwest. This multivariate statistical technique was applied to a spatial array of modern pollen and climatic data in order to derive a set of mathematical transfer functions. These transform the fossil pollen spectra directly into quantitative estimates of past climatic values. The basic sequence of climatic events that is reconstructed is in general agreement with previous studies of postglacial climates in the Midwest, but quantitative estimates for certain of the variables, e.g., temperature and precipitation, are given for the first time.Fossil pollen from three cores collected from lakes in Wisconsin and Minnesota allow a preliminary reconstruction of past east-west and north-south gradients of the climatic variables. Because changes in the circulation patterns in midlatitudes are the principal mechanism causing fluctuations in temperature and precipitation, past records of the atmospheric circulation are reconstructed along with records of temperature and rainfall. The time series derived show that the most pronounced climatic change indicated in Wisconsin and Minnesota occurred at the end of the Pleistocene (the beginning of the Holocene). This change is particularly evident in the climatic variables related to temperature, which rose ca. 3.3°C. A decrease in snowfall also occurred.During the Holocene, the most marked change appears in the results from Kirchner Marsh, where the amount of dry western air began to increase and the precipitation to decrease about 9500 B.P. A reversal of these changes occurred about 5000 B.P. In contrast, relatively little change occurred among the reconstructed values from Wisconsin; a marked east-west precipitation gradient, therefore, developed in this region of the Midwest from 9500 to 5000 B.P.
Absolute Pollen Diagram of Redrock Lake, Boulder County, Colorado
Authors: Maher Louis J. 
Published: December 2004

Redrock Lake is situated at 3,095 m in the subalpine zone on the east flank of the Front Range, Boulder County, Colorado. The lake lies on Pinedale moraine, and it contains 170 cm of organic sediments that overlie 10 cm of silty clay. The oldest of seven 14C dates from the organic sediment is 9,490 ± 150 yr B.P., a minimum estimate of the time since Middle Pinedale ice receded from the lake basin.A percentage pollen diagram and an absolute pollen diagram providing pollen deposition rates in grains/cm2/14C yr are compared and contrasted. Possible measurement errors are considered in detail, and for the first time confidence limits are assigned to all pollen data. A means of converting 14C years to calendar years is presented, and its effect on the diagram's deposition rates is discussed.The silty clay contains a peculiar Artemisia-dominated pollen assemblage with very low pollen influx rates, which suggests the lake was receiving large volumes of glacial meltwater during its early history. The overlying organic sediments are characterized by pollen deposition rates of 4,000–6,000 grains/cm2/yr. With fluctuations, deposition rates of Pinus and total anemophilous pollen increase upward in the core; this evidence for a general upward shift in the region's vegetation zones during Postglacial time is supported by pollen trends from modern surface samples.
Late Quaternary Glacial and Climatic History of Northern Cumberland Peninsula, Baffin Island, N.W.T., Canada
Authors: Miller Gifford H. 
Published: December 2004

AbstractRadiocarbon dates on molluses in marine facies associated with glacial deposits in northern Cumberland Peninsula indicate both main fiord (Laurentide) ice and local glaciers remained at their late Wisconsin maxima until ca. 8000 BP. Essentially continuous deglaciation followed; local corrie glaciers melted out by 7100 BP and by 5500 BP fiord glaciers had receded behind the present margin of the Penny Ice Cap. The Hypsithermal warm interval probably lasted from ca. 8000 to 5000 BP. Lichenometry and radiocarbon dates on peat and buried organic horizons delimit a detailed Neoglacial chronology. Of 46 outlet and corrie glaciers investigated, the oldest Neoglacial moraines are dated lichenometrically at 3200 ± 600 BP. Subsequent advances terminated immediately prior to ca. 1650, 780, 350, and 65 yr BP, the most recent of which marked the most extensive ice coverage during the Neoglacial. The highest occurrence of lateral moraines from late Wisconsin advances of local and Laurentide ice suggest that at the late Wisconsin glacial maximum, depression of snowline varied from 450 m below present at the coast to 350 m below present level in the vicinity of the Penny Ice Cap. Moraines, surrounded by glacial ice and lying above the present steady-state ELA, suggest that during the Hypsithermal snowline was up to ca. 200 m above its present elevation. A radiometrically controlled reconstruction of relative summer paleotemperatures for the postglacial derived independently of lichenometry agrees well with the lichenometric age dating of moraines. The data suggest that between ca. 1650 and 900 BP climatic conditions were unfavorable for glacier growth, whereas the period ca. 800-65 yr BP was one of general glacial activity. During the last decade permanent snow cover has been increasing in the area. Previously reported data on climatic trends in the Canadian Arctic based on palynological analyses are similar to the chronology reported here.
Chronology of Cirque Glaciation, Colorado Front Range
Authors: Benedict James B. 
Published: December 2004

AbstractMoraines and rock glaciers in Front Range cirques record at least four, and possibly five, intervals of Holocene glacier expansion. The earliest and most extensive was the Satanta Peak advance, which deposited multiple terminal moraines near present timberline shortly before 9915 ± 165 BP. By 9200 ± 135 BP, timberline had risen to at least its modern elevation; by 8460 ± 140 BP, patterned ground on Satanta Peak moraines had become inactive. Although a minor ice advance may have occurred just prior to 7900 ± 130 BP, there is no evidence that glaciers or perennial snowbanks survived in the Front Range during the “Altithermal” maximum (ca. 7500–6000 BP), or during a subsequent interval of alpine soil formation (ca. 6000–5000 BP).Glaciers were larger during the Triple Lakes advance (5000–3000 BP) than at any other time during Neoglaciation. Minimum ages of 4485 ± 100 BP, 3865 ± 100 BP, and ca. 3150 BP apply to a threefold sequence of Triple Lakes deposits in Arapaho Cirque. After an important interval of soil formation and cavernous weathering, glaciers and rock glaciers of the Audubon advance (1850–950 BP) reoccupied many cirques, and perennial snowbanks blanketed much of the area above present timberline; although the general Audubon snow cover had begun to melt from valley floors by 1505 ± 95 BP, expanded snowbanks lingered on tundra ridge crests until 1050–1150 BP, and glaciers persisted is sheltered cirques until at least 955 ± 95 BP. Following a minor interval of ice retreat, glaciers of the Arapaho Peak advance (300–100 BP) deposited multiple moraines in favorably oriented cirques.Interpretation of Holocene glacial deposits in the Southern and Central Rocky Mountains has been hampered by (1) a heavy reliance upon relative-dating criteria, many of which are influenced by factors other than age; (2) the assumption that glacial advances in high-altitude cirques can be correlated directly with alluvial deposition in far-distant lowlands; and (3) the assumption that glacial advances have necessarily been synchronous throughout the Rocky Mountain region and the world. Although Holocene glacier fluctuations in the Front Range are believed to reflect changes in regional climate, the Front Range chronology does not have particularly close analogs in other parts of North America. Better-dated local sequences are needed before the hypothesis of global synchroneity can be adequately evaluated; until synchroneity has been proven, long-distance correlations and worldwide cycles of recurring glaciation will remain unconvincing.
Correlation of Marine and Continental Quaternary Pollen Records from the Northeast Pacific and Western Washington
Authors: Heusser Calvin J. , Florer Linda E. 
Published: December 2004

AbstractLate-glacial and postglacial pollen stratigraphy and radiocarbon chronology of a marine core from the continental slope and a core from the western Olympic Peninsula, ca. 110 km apart, are compared. Divisible into four pollen assemblage zones (L, P-1, P-2, and P-3), the cores exhibit a succession of correlative zonal prominences: grass-sedge (L), pine (P-1), alder (P-1-P-2 boundary), and hemlock (P-3). Volcanic ash of Mt. Mazama provenance is also correlative in zone P-2. Quantitative relationships of the pollen in the cores (relative and absolute numbers and pollen influx) are dissimilar, however, and are attributed to the influence of the Columbia River pollen load reaching the locale of the continental slope core compared with the local pollen rain influencing the Olympic Peninsula core site.
Paleoenvironments and Cultural Diversity in Late Pleistocene South America
Authors: Bryan Alan L. 
Published: December 2004

AbstractAfter a summary assessment of certain selected early man sites in various parts of America, the environment of the Venezuelan coastal plain is discussed in order to evaluate the stratigraphy and radiometric dating of the Taima-Taima site, near Coro, Venezuela, where mammals, many now extinct, were killed by people making El Jobo points about 13,000 years ago.Potentially important areas in Peru, Chile and Brazil are mentioned. Certain problems in the models and interpretation of South American paleoclimates are pointed out.The presence of at least four different bifacially flaked stone projectile point traditions in widely separated and environmentally diverse parts of America between 11,000 and 13,000 yr ago suggests that the immediate cultural antecedents of these traditions were essentially independent of one another. From this it is argued that several early American flaked-stone point traditions developed indigenously in America from technological bases which were present in the Old World Middle Paleolithic.
Sediment Analysis of a Prehistoric Rockshelter: The Abri Pataud
Authors: Farrand William R. 
Published: December 2004

AbstractRockshelter and cave-mouth deposits accumulate in specialized niches through the breakdown of the enclosing bedrock, the addition of windblown and fluvial sediment and, in the case of prehistoric sites, human habitation debris. Certain modifications of routine sediment analysis are necessary in order to realize the full potential of paleoenvironmental interpretation. These sediments are coarse, necessitating the collection of large samples, commonly 10–20 kg. The size and shape of the coarse fraction yields information on rockfalls, freeze-thaw activity, and weathering effects. Travertine and soil-carbonate coatings on the rock fragments indicate variations in ambient humidity and soil formation, respectively. Studies of the granulometry, mineralogy, and geochemistry of the fine fraction lead to conclusions concerning primarily the postdepositional modification of the sediments. Heavy minerals can be important in determining the provenience of the fine sediment. These methods of analysis are discussed in detail with the Abri Pataud as a specific example, and caution is urged in making regional generalizations from the study of a single site.
Note on Pollen Extraction from Coarse Sediments
Authors: Juvigné E. 
Published: December 2004

AbstractThe following note on a new method for extracting pollen from fossil pollen grains summarizes two articles in French, published in Annales de la Société Géologique de Belgique (Juvigné, 1973a; 1973b).The new method proposed has three important parts: (1) Elutriation of the sediment in water; (2) the specific gravity of the heavy liquid must be between 2.25 and 2.5; and (3) the dispersion of the sediment in the heavy liquid is made with a high-speed mixer.
Time Series and Postglacial Forest Ecology
Authors: Green David G. 
Published: December 2004

AbstractForest ecology suffers from a lack of long-term community records. Preserved pollen data are richer in such information than is generally realized. By applying suitable statistical techniques to pollen records, one can learn much about competition, succession, and population dynamics in past tree communities. In this study, preserved pollen records from Everitt Lake, Nova Scotia, are analyzed as time series. Time domain studies reveal the post-fire responses of individual tree taxa. Correlograms yield models of past forest succession patterns. The models explain some effects of changing fire frequency, thus suggesting mechanisms by which fire, competition, and climate combine to produce long-term forest composition changes. Frequency domain studies suggest relationships between disturbance cycles, stand composition, and forest mosaics. Fire frequencies are seen to be highest where fire-dependent species abound and most regular where tree stands have uniform, not mixed, composition.
The Selection of Sites for Paleovegetational Studies
Authors: Jacobson G. L. , Bradshaw R. H. W. 
Published: December 2004

AbstractThe judicious selection of sites for paleovegetational and paleoclimatic studies permits paleoecologists to answer specific research questions that go beyond primary descriptions of past vegetation. We present a model that describes the relationship between basin size and pollen source area and predicts the proportions of local, extralocal, and regional pollen sampled by lake basins of different size. The distinctive sampling properties of lakes, peats, and small hollows can be exploited to provide details of pattern in paleovegetation so long as attention is given to the limitations and problems of these types of sites. Combinations of site types in a single study most fully exploit the information contained in sediments.
Fire and Other Disturbances of the Forests in Mount Rainier National Park
Authors: Hemstrom Miles A. , Franklin Jerry F. 
Published: December 2004

AbstractThe recent history of catastrophic disturbances in forests was reconstructed at Mount Rainier National Park. Basic data were ages of trees based on ring counts of early seral conifer species and maps of age-class boundaries from field work and aerial photographs. Maps illustrate age classes of the forests and show disturbances from fires, snow avalanches, and lahars (volcanic mudflows). Fires are by far the most important major disturbers, followed by snow avalanches and lahars. Fires over 250 ha in size are called fire events. Burns over 1000 ha, which may have been one fire or a series of fires within a short time, are called fire episodes. Important fire events or episodes occurred in the years 1230, 1303, 1403, 1503, 1628, 1688, 1703, 1803, 1825, 1856, 1858, 1872, 1886, 1894, 1930, and 1934 A.D. The largest fire episode was in 1230; it affected approximately 47% of the forests in the park. The majority of the forests are over 350 yr old, and several stands are over 1000 yr old. Stands 350 yr and 100 to 200 yr in age are the most extensive age classes in the park. Three fire frequency indices are compared. None describe fire frequency at Mount Rainier well. Natural fire rotation was estimated at about 434 yr. All but two episodes of major fires since 1300 A.D. correspond well with major droughts reconstructed for locations east of the Cascade Range crest. Impacts of humans on the disturbance regime may have increased the frequency of fire in the 1850–1900 period, followed by a decrease in frequency after 1900. Fuel build-up as a result of fire suppression should have no significant impact on fire frequency, since fires are relatively infrequent and fuels accumulate naturally.