bluuebunny/crossref_metadata_2025_split huggingface dataset:
2‐Ketoglutarate dehydrogenase deficiency, a rare cause of primary hyperlactataemia: Report of a new case
Authors: Guffon N. , Lopez‐Mediavilla C. , Dumoulin R. , Mousson B. , Godinot C. , Carrier H. , Collombet J. M. , Divry P. , Mathieu M. , Guibaud P. 
Published: December 2004

SummaryTwo new familial cases of 2‐ketoglutarate dehydrogenase (2‐KGD) deficiency are reported: a girl who died at 10 years and a boy, still alive at 4 years, born to consanguineous parents. The cases developed progressively severe encephalopathy with axial hypotonia, psychotic behaviour, pyramidal symptoms and failure to thrive. Both children exhibited permanent lactic acidosis with acute episodes during emotional stress and various infections, associated with elevated lactate/pyruvate (L/P) ratio and slightly decreased ketone body ratio in plasma. In fibroblasts, the L/P ratio was greatly increased in the boy. No respiratory chain complex deficiency could be demonstrated in cultured fibroblasts or in mitochondria isolated from a muscle biopsy performed on the boy. In muscle isolated mitochondria, a progressive decrease of the rate of glutamate oxidation was observed after ADP addition; the rate of 2‐ketoglutarate oxidation was low in the absence of ADP and did not increase after ADP addition. 2‐KGD deficiency was demonstrated in fibroblasts from both children and in the boy's muscle and myoblasts. The 2‐KGD complex is composed of three separate enzymes: E1, E2 and E3. We could demonstrate in our patient that the E1 and E3 subunits were normal, suggesting that the E2 component could be responsible for the defect.
Reliable prenatal diagnosis of Canavan disease (aspartoacylase deficiency): Comparison of enzymatic and metabolite analysis
Authors: Bennett M. J. , Gibson K. M. , Sherwood W. G. , Divry P. , Rolland M. O. , Elpeleg O. N. , Rinaldo P. , Jakobs C. 
Published: December 2004

SummaryPrenatal diagnosis has been undertaken in 17 pregnancies in 15 families at risk for aspartoacylase deficiency. Amniocentesis was at 14–18 weeks gestation followed by measurement of amniotic fluidN‐acetyl‐l‐aspartate (NAA) levels in all pregnancies and amniocyte aspartoacylase activity in most pregnancies. In one case amniocentesis was performed at 11 weeks gestation in conjunction with chorionic villus sampling. At 14–18 weeks of gestation, control levels of NAA were 0.30–2.55 µmol/L. The fetus was predicted to be affected in 8 of the pregnancies, 4 of which were confirmed by enzyme analysis on fetal tissue and 2 by the clinical and metabolic expression of Canavan disease in a newborn. In two cases there was no fetal tissue available for enzyme confirmation. One of these had the highest amniotic fluid NAA level (8.68 µmol/L) and in the other pregnancy there were two amniocenteses, both with markedly elevated levels. Of 9 fetuses predicted to be normal, 8 newborns were clinically and biochemically normal. A single case with amniotic fluid NAA in the normal range (1.56 µmol/L, measured in one laboratory only) resulted in an aborted fetus in whom aspartoacylase was deficient in cultured skin fibroblasts. We propose that amniotic fluid NAA levels remain the best predictor of an affected fetus and recommend that the assay be performed in multiple laboratories.
Prenatal analysis in two suspected cases of glutathione synthetase deficiency
Authors: Erasmus E. , Mienie L. J. , de Vries W. N. , de Wet W. J. , Carlsson B. , Larsson A. 
Published: December 2004

SummaryPrenatal diagnosis was performed in a family affected by generalized glutathione synthetase deficiency. The disorder is transmitted by autosomal recessive inheritance. The first child born in this family died of the disorder at 6 weeks of age. Prenatal diagnosis was performed in two subsequent pregnancies. Amniotic fluid samples were collected by amniocentesis in the 16th and 17th weeks of pregnancy, respectively. In the case of the second pregnancy the concentration of 5‐oxoproline in the amniotic fluid was measured by stable isotope dilution, while both stable isotope dilution and glutathione synthetase activity measurements were employed in the prenatal analysis of the third pregnancy. The 5‐oxoproline concentration in the second pregnancy was even lower than that of the controls and in the case of the third pregnancy the results fell within the control range. The second pregnancy resulted in the birth of a clinically healthy girl, and the outcome of 5‐oxoproline concentration in a urine sample taken just after birth confirmed the unaffected state. The third pregnancy resulted in the birth of a healthy boy at term, and the 5‐oxoproline concentration in his urine and the glutathione synthetase activity in haemolysates were determined. The results confirmed that this infant was also unaffected and he apparently had two normal alleles for the enzyme.
Late Quaternary Climates of Australia and New Guinea
Authors: Bowler J.M. , Hope G.S. , Jennings J.N. , Singh G. , Walker D. 
Published: December 2004

Between 60,000 and 40,000 B.P., northeastern Queensland, south New South Wales, and southeastern South Australia were drier than at present. From 40,000–30,000 B.P. a colder climate than at present is indicated from one New Guinea area. Dryness became even more accentuated in northeastern Queensland, whereas many lakes filled up in the southern mainland, probably because of increasing precipitation effectiveness there. Before the end of this period colder conditions than now were already giving rise to slope instability in the Snowy Mountains of New South Wales.The period of 25,000–15,000 B.P. saw the greatest lowering of the New Guinea treeline, reaching an extreme at 17,000 B.P. when glaciers also achieved their maximum extent. This was the time of extensive glaciation in Tasmania and small glaciers formed in the Snowy Mountains. Estimates of the lowering of mean annual temperature range from 6°–10°C. Northeastern Queensland experienced its driest Late Quaternary climate; lakes were contracting throughout the southern mainland and the final phase of substantial desert dune building took place before the period ended.In the Snowy Mountains ice retreat began before 20,000 B.P., as did the construction of clay dunes in the southern semi-arid belt, a process demanding higher temperatures. However, in New Guinea and Tasmania ice retreat and treeline rise did not begin till after 15,000 B.P. Temperatures rose rapidly and everywhere most of the ice had gone by 10,000 B.P., when some lakes filled up in southern Australia, implying an increase in absolute precipitation.In the last 10,000 years climate has been relatively stable although there are some indications that temperature and rainfall were marginally higher than now between 8000 and 5000 B.P. Since then, lake levels have oscillated; a brief, limited resumption of periglacial activity took place in the Snowy Mountains and there were small glacier advances in New Guinea.
Heavy Minerals and the Evolution of the Modern Nile
Authors: Hassan Fekri A. 
Published: December 2004

Heavy mineral analysis is a useful tool in tracing the changes in the hydrographic setting of the Nile through time. Analyses by the writer and others are presented to differentiate between a former Nilotic system, a Proto-Nile, and the modern Nile system, and to demonstrate the changes undergone by the modern Nile.The Proto-Nile was almost totally dependent upon discharge from equatorial and sub-equatorial tributaries in East Africa and from local Sudano-Egyptian affluents. The modern Nile system, in contrast, is dominated by contributions from the Blue Nile and the Atbara River, which drain the Ethiopian Plateau. The discharge of these rivers is governed by the monsoonal rains which are responsible for the summer floods in the Lower Nile Basin. It has been generally believed that this riverine system is very recent, perhaps not much older than 20,000 years. The evidence presented in this paper indicates that the Modern Nile system was well established by the later part of the Middle Pleistocene. In its early stage, the modern Nile was characterized by greater contributions from the non-Ethiopian East African and Sudano-Egyptian tributaries than at present.
Estimates of the Position of Sea Level between 140,000 and 75,000 Years ago
Authors: Stearns Charles E. 
Published: December 2004

The absolute elevations of sea level 103,000 and 82,000 years ago have been estimated as −15 and −13 m, respectively, from the present elevations of emergent reefs on Barbados (Broecker et al., 1968; Matthews, 1973; Bloom et al., 1974). The “Barbados model” requires two assumptions: (1) that sea level was +6 m 124,000 years ago, and (2) that rates of uplift on short individual traverses have been uniform during the last 125,000 years.A test of the derived values on Barbados itself does not yield uniform rates of uplift between 124,000 and 82,000 years ago. Less reliably dated strand line features on less uplifted coasts suggest that sea level 124,000 years ago differed from sea levels 103,000 and 82,000 years ago by smaller amounts than those suggested by the “Barbados model.” Such smaller differences yield more uniform rates of uplift between 124,000 and 82,000 years ago, on New Guinea as well as on Barbados, than do the larger. The “Barbados model” is not sufficiently precise to yield close estimates of past elevations of sea level. Better values will eventually be derived from low uplift coasts, when stratigraphic and radiometric data from them have achieved the credibility of data from moderate to high uplift coasts.
Slope Deposits in the Snowy Mountains, South-Eastern Australia
Authors: Costin A. B. , Polach H. A. 
Published: December 2004

Slope deposits in the Snowy Mountains of south-eastern Australia have a wide distribution above 1000 m elevation on slopes between approximately 5° and 25° which are well stabilized by the existing forest vegetation. The present environment is not severe enough to initiate slope instability.The slope deposits consist of fines with gravel and angular stones showing preferred downslope orientation, overlying a generally smooth substrate of weathered bedrock. Pockets and lenses of relatively stone-free organomineral soil containing fragments of carbonized wood sometimes occur near the interface between the slope deposits and the weathered bedrock. Fragments of the carbonized wood carefully selected from three sites in different catchment areas several kilometers apart have similar radiometric ages of between 31,000 and 34,000 years.The properties of the slope deposits and the context of the site and climatic conditions in which they now occur point to an origin under periglacial conditions commencing 31,000–34,000 years ago, associated with deep seasonal freezing and thawing although not necessarily with permafrost. It is estimated that a substantially lower mean annual temperature, at least 8–10°C less than the present, would have been necessary to produce periglacial conditions down to 1000 m in the Snowy Mountains. On the evidence of similar slope deposits elsewhere in south-eastern Australia, this major cold period was evidently widespread.Climatic conditions prior to the onset of the cold period appear to have been generally similar to those of today, except perhaps for rather moister and cooler summers.
Pollen Grains in Lake Sediments: Pollen Percentages in Surface Sediments from Southern Michigan
Authors: Davis M. B. , Brubaker L. B. , Beiswenger J. M. 
Published: December 2004

Pollen in surface sediments from five lakes in southern Michigan shows evidence of differential deposition. In most lakes, pollen from ragweed occurs in a higher ratio to tree pollen in shallow-water sediment than in deep water. Pine and certain herbs with small pollen grains follow the same pattern. One very deep lake is an exception, with the ratio of ragweed to tree pollen highest in deep-water sediment. Pollen from local aquatics and from willow, which grows along the lake shore, is also unevenly distributed, occurring in highest frequencies near the parent plants. Pollen from deciduous trees, however, occurs in similar ratios at all sampling stations within each lake. Deciduous pollen occurs in uniform ratios, also in older sediment, deposited in the early 19th century, when the landscape was still forested.Percentages of deciduous tree pollen (as percent tree pollen) were compared among lakes. Single samples were taken for this purpose from the deepest part of each lake basin. Oak pollen percentages are higher in three lakes in western Washtenaw County than in three lakes in eastern Washtenaw County. This difference reflects a similar difference in present-day vegetation: second-growth oak forests grow near the lakes in the western half of the county, while all but 5% of the area in the eastern part of the county is farmland. (The difference in the ratio of farmland to forestland in the two parts of the county is not reflected clearly in the ratio of herb pollen to tree pollen, because there is so much variation within each lake.) In 140-year-old sediment, on the other hand, tree pollen percentages in the six samples are homogeneous as shown by a chi-square test. The homogeneity in sediment deposited before the forest was cleared is surprising, because witness-tree data from presettlement time show that the frequencies of tree species in the two areas were quite different. Pollen dispersal at that time must have been effective enough, to counteract differences over distances of a few tens of kilometers in the amounts and kinds of pollen produced by the vegetation.
Glacio-Periglacial Landforms within the Susquehanna Great Bend Area of New York and Pennsylvania
Authors: King Cuchlaine A.M. , Coates Donald R. 
Published: December 2004

AbstractPrevious attention has been called to the morphology of the glaciated Appalachian Plateau, including periglacial phenomena (Coates, 1970; Conners, 1969). This paper deals with an unusually well-developed hierarchy of small landforms in the Great Bend area of the Susquehanna River. Essential properties of these features include: (1) concentration in N-S valleys, (2) till composition, (3) concavo-convex form, sometimes ending in a hill on the valley floor, (4) alternation with steep, truncated bedrock spurs, (5) a col in the interfluve at their head. These characteristics could be explained by the following sequence of events. A prior fluvial landscape was eroded with tributary streams forming lateral valleys that head in cols along the divides. The main stream flowed south between interlocking spurs. Ice then widened the valley, leaving truncated spurs and a straightened stream. Deposition of locally derived till filled tributary valleys, similar to till shadows (Coates, 1966). In periglacial conditions, while nivation was widening the tributary valley heads, solifluction in the unstable till was forming the concavo-convexities that alternate with the truncated bedrock spurs. The hierarchy of forms range from minor convexities to small hills on the main valley floor. Thus, the features are primarily of periglacial origin, but owe their development and position to prior subaerial and glacial events. The cycle may have occurred during more than a single glacial episode. The recession of bedrock spurs and the valley floor convexity of the till features have caused a reversal in stream sinuosity of the main valley.
Pleistocene Chronology: Long or Short?
Authors: Cooke H.B.S. 
Published: December 2004

AbstractEuropean geologists, in general, have tended to favor a “short” chronology for the glacial Pleistocene, with four major glacial cycles in the past 500,000 or 600,000 yr. Interpretation of ocean floor sediments by Emiliani and others has accorded with this view, in contrast to the “long” chronology of Ericson and Wollin and their followers, who spread the four North American glacial episodes over a 2-m.y. period. An examination of the available radiometric dates and age estimates from paleomagnetic polarity zones serves to confirm Richmond's view that the four major European glacials do not equate with the four North American glacials in a simple one-to-one manner, but that the Illinoian matches the Elster (Mindel) rather than the Saale (Riss). The Alpine Günz is then equated broadly with the Kansan and overlaps in time with the Jaramillo normal polarity event at about 900,000 y.a. The Nebraskan is older than 1.2 m.y. and is thus coeval with the European Upper Villafranchian, within which the Donau and Biber glacial events may be traced. Montane glaciation certainly extended back into the Tertiary but cold pulses of sufficient duration to produce continental glaciation were more marked through the past 1.5 m.y. More critical studies of the terrestrial record are needed before firm correlations can be made.
Late-Quaternary Sea Level Changes, Umnak Island, Aleutians—Their Effects on Ancient Aleuts and their Causes
Authors: Black Robert F. 
Published: December 2004

Late-Quaternary sea level changes in the eastern Aleutian Islands are of paramount importance in the reconstruction of the migrations and environment of the ancient Aleuts. A radiocarbon-dated ash stratigraphy provides the chronology into which geomorphic events can be fitted. These provide evidence for the sea level changes. Deployment of beach material and coastal configuration intimate that sea level was about 2–3 m above the present level about 8250 radiocarbon yr BP. Beach deposits suggest that sea level remained high until about 3000 radiocarbon y.a. when it gradually dropped to its present position. It is concluded that the ancient Aleuts that settled Anangula about 8400 y.a. used boats; all major passes in the eastern Aleutians were flooded, and did not have winter ice. Those ancient Aleuts did not have available the major year-around food resources of the present strandflats as they were cut during the high sea level stand 8250–3000 yr BP. The ancient Aleuts must have been marine oriented, for land-based food resources would have been limited.The cause of relative sea level changes on Umnak Island is considered indeterminate with present data. Eustatic, glacial isostatic, water isostatic, tectonic, and volcanic causes are considered the main possible controls in combinations such that a basic eustatic sea level curve and likely a glacial-water isostatic curve must be common to any solution. Representative solutions are given to illustrate some of the problems.
The Deglaciation History of the Lake Superior Region and its Climatic Implications
Authors: Saarnisto Matti 
Published: December 2004

A zone of synchronous end moraines has been recognized in the Lake Superior region across northern Ontario and Michigan. The moraines were formed between 11,000 and 10,100 y.a. as cold climate resulted in successive halts in the general ice retreat. The cold climate is also indicated by the presence of tundra near Lake Superior until about 10,000 y.a. This episode is here referred to as the Algonquin Stadial. It was preceded and followed by rapid deglaciation. The Algonquin Stadial is comparable in age with the Younger Dryas Stadial of Europe, and indicates a reversal in the continuous trend toward a warmer climate during Late-Wisconsin (an) time. The apparent conflict between the present result (based on geologic evidence) and earlier pollen stratigraphical studies with no reversal is discussed.Glacial Lake Duluth formed in the western Lake Superior basin before 11,000 BP, followed by a series of Post-Duluth lakes between approximately 11,000 and over 10,100 BP. The Main Lake Algonquin stage in the Huron and Michigan basins terminated approximately 11,000 BP. The subsequent high-level post-Main Algonquin lakes, which were contemporaneous with the Post-Duluth lakes, existed in the southeastern Lake Superior basin. When the ice margin was along the north shore 9500 BP Lake Minong occupied the whole Lake Superior basin. By 9000 BP the ice had retreated north of Lake Superior-Hudson Bay divide.
A Climatic Model of Solar Radiation and Temperature Change
Authors: Reitan Clayton H. 
Published: December 2004

Mean monthly temperatures for the Northern Hemisphere were determined for the years 1955 through 1968 following the same procedures used by H. C. Willett and J. M. Mitchell, Jr., in their studies of long-term trends. It was found that the downward trend they reported starting in the 1940s continued, though interrupted, into the 1960s.The temperature data when combined with radiation data and other components of the hemispheric energy budget led to the formulation of the response ratio, the relationship between change in incoming solar radiation and change in temperature. When this response ratio was applied to the reported trends in direct solar radiation and to the decrease in direct solar radiation following the eruption of Agung in 1963, a probable cause-effect relationship was suggested.
Lichenometry on Calcareous Substrates in the Canadian Rockies
Authors: Osborn Gerald , Taylor John 
Published: December 2004

AbstractLichen distribution and growth were examined at several sites in the Canadian Rockies between Mt. Robson and Banff townsite to determine the feasibility of lichenometry on calcareous deposits. The only lichen common enough to be of use is Xanthoria elegans, a bright orange lichen with round or elliptical thalli. It is not an ideal species for lichenometry because (a) it grows fairly quickly and has a range of only a few centuries, (b) growth is influenced by the presence of animal dung, (c) parts of some thalli weather away before maximum size is attained, (d) thalli may thicken as well as grow laterally with age, (e) the species is succeeded by other species relatively quickly in heavily forested environments, and (f) the species is not abundant on some deposits due to sometimes-unexplained environmental influences. However, when used with caution the species is still useful for dating purposes.A growth curve for Xanthoria elegans was developed using moraines dated dendro-chronologically and man-made structures. After an ecesis interval of one or two decades the lichen grows at a rate of 0.68 mm/yr for several decades, then slows down to a rate of 0.22 mm/yr.