bluuebunny/crossref_metadata_2025 huggingface dataset:
A 30,000 yr Continental Paleotemperature Record Derived from Noble Gases Dissolved in Groundwater from the San Juan Basin, New Mexico
Authors: Stute Martin , Clark Jordan F. , Schlosser Peter , Broecker Wallace S. , Bonani Georges
Published: October 2002

Paleotemperatures for the last glacial maximum (LGM) have been derived from noble gases dissolved in 14C-dated groundwater of the Ojo Alamo and the Nacimiento formations in the San Juan Basin, northwestern New Mexico. The difference in mean annual (ground) temperature between the Holocene and the LGM was determined to be 5.5 ± 0.7°C. A practically identical result, 5.2 ± 0.7°C, has been obtained previously from the Carrizo aquifer in southern Texas. This suggests that the southwestern United States was uniformly cooler during the LGM and that the mean annual temperature gradient along a transect from the Gulf of Mexico to northwestern New Mexico has been unchanged since the LGM. The noble gas paleotemperatures are supported by paleoecological evidence in the region. The Holocene/LGM temperature difference of 5.4°C indicates that a simple lapse rate calculation may be applied to convert the 1000-m glacial depression of snowlines in the Colorado Front Range into a temperature decrease. A continental temperature change of 5.4 ± 0.7°C is inconsistent with a temperature change of about 2°C determined for the surface waters of the Gulf of Mexico.
A Late-Glacial/Holocene Pollen Record from the Eastern Andes of Northern Peru
Authors: Hansen Barbara C.S. , Rodbell Donald T.
Published: October 2002

A pollen and sediment record of a core 4.2-m-long from Laguna Baja (7°42′ S, 77°32′ W, 3575 m) in the Cordillera Oriental of northern Peru suggests several episodes of major vegetational and climatic change over the past 13,000 yr. The oldest pollen assemblage consists of a mixture of paramo elements (tropical alpine vegetation), including high percentages of Poaceae (40%) that decline upward, moist montane forest (Compositae and Polylepis), and wet montane forest (e.g., Hedyosmum and Podocarpaceae). Organic carbon content range from <2% to 8%. About 11,600 yr B.P. this mixed pollen assemblage was replaced by Poaceae (>60%), with high percentages of Jamesonia, a fern characteristic of paramo and decreasing values of Plantago tubulosa and the wet montane forest elements Hedyosmum and Podocarpaceae. Charcoal percentages are at a maximum during this period, magnetic susceptibility and sand percentages are high, and percentages of organic matter are low. Several explanations for these changes are possible, including a reduction in temperature and moisture, more frequent periods of aridity with increased fires, or natural succession. The Holocene record begins with pronounced increases in organic carbon and pollen of wet montane forest, primarily Hedyosmum , Podacarpaceae, and Urticales. High values of Podocarpaceae pollen (>35%) and a decline in charcoal suggest temperature and moisture levels above modern-day values. Wet montane forest pollen remain high and charcoal values are low from about 10,000 to 6000 yr B.P., suggesting that warm and moist conditions prevailed for about 4000 yr. Subsequently Podocarpaceae and Urticales decline, and for a brief time Alnus is prominent in the pollen record. Following the Alnus maximum at about 5000 yr B.P., Poaceae, Ambrosia and Chenopodiaceae/Amaranthaceae become frequent. Increased paramo and disturbance indicator pollen suggest increased anthropogenic activities in this region from the middle Holocene to the present.
Late Quaternary Vegetational and Climatic Changes in the Pampa Grassland of Argentina
Authors: Prieto Aldo Raúl
Published: October 2002

The vegetation and climate of the Pampa grassland, Argentina, during the late Quaternary are reconstructed from pollen recovered from dated stratigraphic sections from arroyo walls and from archaelogical excavations. Prior to 10,500 yr B.P., herbaceous psammophytic steppe existed in the central part of the Pampa grassland while xerophytic woodland associated with psammophytic and halophytic steppe occurred in the southwestern part of the Pampa. These types of vegetation and the continental conditions that prevailed in the area of the present-day coast (38°S), indicate subhumid-dry climate and annual precipitation 100 mm lower than present. A subsequent change toward a vegetation characteristic of ponds, swamps, and foodplains, or toward environments with locally more effective moisture, occurred ca. 10,500 yr B.P. suggesting annual precipitation close to modern levels or a higher availability of water in the central part of the Pampa grassland, this type of vegetation existed until 8000 yr B.P., when it was replaced by grassland communities that lasted until 7000 yr B.P. In the southwestern part of the Pampa grassland, this vegetation developed before 7000 yr B.P. and persisted until ca. 5000 yr B.P. Sea level higher than the present ca. 6200 yr B.P. is consistent with sharp modification of the vegetation and development of local halophytic communities dominant at 38°S. A return to subhumid-dry conditions occurred after 5000 yr B.P. The late Holocene vegetation is characterized by pollen assemblages similar to the psammophytic and halophytic communities of the Southern pampa grassland, associated with communities with more edaphic conditions. At the same time, at 38°S a sea level regression is suggested by the dominance of fresh-water pollen assemblages and micropaleontological remains. The trend toward humid, temperate conditions ca. 1000 yr B.P. suggested by vertebrate remains characteristic of temperate and humid conditions, as well as a very short but dry episode during the 18th century suggested by the geology, are not clearly evidenced in the pollen sequences. Vegetational and climatic changes are explained by the latitudinal shifts and changes in intensity of the southern atmospheric circulation and changes in sea level.
Size Variation in the Rock Hyrax (Procavia capensis) and Late Quaternary Climatic Change in South Africa
Authors: Klein Richard G. , Cruz-Uribe Kathryn
Published: October 2002

The average adult size of the rock hyrax varies greatly across South Africa. Regression analysis suggests that mean hyrax size is more closely linked to precipitation than to temperature, probably because precipitation has a much greater impact on preferred hyrax food plants. The relationship between mean size and precipitation is curvilinear, such that size increases up to about 700 mm/annum and declines thereafter. This parallels a tendency for less palatable grasses to replace more palatable ones where rainfall exceeds 700 mm/annum. In conjunction with other indicators of past climate, hyrax size variation can be used to reconstruct precipitation history near deeply stratified South African late Quaternary sites, including Elands Bay Cave, Die Kelders Cave 1, and Nelson Bay Cave.
Palynological and Radiocarbon Evidence for Deglaciation Events in the Green Bay Lobe, Wisconsin
Authors: Maher Louis J. , Mickelson David M.
Published: October 2002

A new and significant site of organic silty sand has been found beneath the Valders till at Valders Quarry in northeastern Wisconsin. This is now the earliest known late-glacial site associated with red till ice advances in the western Great Lakes area. Leaves of terrestrial plants washed into a small depression provide a date of 12,965 ± 200 yr B.P. (WIS-2293), which is significantly older than the Two Creeks Forest Bed (ca. 11,800 yr B.P.). Percentage and concentration pollen diagrams suggest that the site was open and distant from a closed Picea forest. No wood or Picea needles have been found. This date is statistically indistinguishable from 12,550 ± 233 yr B.P., the mean of three dates for the end of inorganic varve sedimentation at Devils Lake, 160 km southwest at the terminus of the Green Bay Lobe. Assuming that the Green Bay lobe vacated its outermost moraine in the interval from 13,000 to 12,500 yr B.P., only a short time was available for retreat of the ice margin over 350 km, drainage of red sediment from Lake Superior into the Lake Michigan basin, readvance of over 250 km, retreat of at least 80 km, and advance to this site. The time for these events appears to have been too short to resolve by current radiocarbon technique. This extremely rapid collapse of the Green Bay lobe has a calibrated age of about 15,000 cal yr B.P., about that of the dramatic warming seen in the Greenland ice cores.
Origin and Evolution of Lunettes on the High Plains of Texas and New Mexico
Authors: Holliday Vance T.
Published: October 2002

Lunettes—isolated dunes on the lee side of playa basins—are common landforms on the Southern High Plains of northwest Texas and eastern New Mexico. The dunes contain calcareous (15–40% CaCO3) sandy loam or loamy sand, with minor amounts of sepiolite, deposited 25,000–800014C yr B.P. and derived by deflation of lacustrine carbonate in the basins. The dunes also contain low carbonate (0–15% CaCO3) sand or loamy sand that was deposited 25,000–15,000 yr B.P. and 8000–5000 yr B.P. and was derived by deflation that created the basins or deflated from sand deposited in the basins. Buried soils are common in the lunettes: A-Bk profiles characterize soils formed in the calcareous sandy loam; the sandy low-carbonate sediments contain A-Bt profiles in the oldest sand of some dunes, and A-Bw, A-Bt, or A-Btk in the early and middle Holocene sand. The dune stratigraphy, combined with carbon isotope data (derived from dated A-horizons in lunettes), suggests the following scenario for the Southern High Plains. The lunettes began forming as low-carbonate sand dunes in the late Pleistocene as playa basins were formed or deepened by wind erosion. The erosion repeatedly alternated with stability. The environment probably was cool and dry, but one or more cool and wet intervals 25,000–15,000 yr B.P. resulted in a rise in the water table and deposition of lacustrine carbonate in the deepest basins. There may have been short departures toward warmer (and probably toward drier) conditions throughout this time. Episodically dry conditions 15,000–8,000 yr B.P. resulted in deflation of the carbonate and further dune construction by repeated accretion of calcareous sandy loam or loamy sand. The low carbonate sand was deposited during widespread drought and deflation 8000–5000 yr B.P. The dunes have been largely stable in the late Holocene.
Correlation of Late-Pleistocene Lake-Level Oscillations in Mono Lake, California, with North Atlantic Climate Events
Authors: Benson Larry V. , Lund Steve P. , Burdett James W. , Kashgarian Michaele , Rose Timothy P. , Smoot Joseph P. , Schwartz Martha
Published: October 2002

Oxygen-18 (18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard–Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest lowstand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent lowstands occurred at the same times as Heinrich events H1, H2, and H4.18O data indicate the two highest lake levels occurred ∼18,000 and ∼13,100 14C yr B.P., corresponding to passages of the mean position of the polar jet stream over the Mono Basin. Extremely low values of total inorganic carbon between 26,000 and 14,000 14C yr B.P. indicate glacial activity, corresponding to a time when summer insolation was much reduced.
Encoding, Decoding and Data Refinement
Authors: Back Ralph-Johan , von Wright Joakim
Published: October 2002

Data refinement is the systematic replacement of a data structure with another one in program development. Data refinement between program statements can on an abstract level be described as a commutativity property where the abstraction relationship between the data structures involved is represented by an abstract statement (adecoding). We generalise the traditional notion of data refinement by defining anencoding operatorthat describes the least (most abstract) data refinement with respect to a given abstraction. We investigate the categorical and algebraic properties of encoding and describe a number of special cases, which include traditional notions of data refinement. The dual operator of encoding isdecoding, which we investigate and give an intuitive interpretation to. Finally we show a number of applications of encoding and decoding.
Creating local knowledge through learning in community: A case study
Authors: Stein David S.
Published: October 2002

Learning in community means creating local knowledge from aspects of communal life. Through a six‐stage process, adult educators can help community members become independent learners and co‐creators of community knowledge.
Does jury deliberation really improve jurors' memories?
Authors: Pritchard Mary E. , Keenan Janice M.
Published: October 2002

The courts assume that jury deliberation corrects errors in jurors' memories, so that the verdict is based on accurate memory for the trial. We evaluated the validity of this assumption by examining jurors' memories and verdicts both before and after deliberation. Unlike previous studies, we tracked how event memories changed as a function of how they were discussed in deliberation. Overall, deliberation resulted in only a slight memory improvement. Deliberation corrected errors and did not introduce distortions. Reasons for such slight memory improvement are that jurors did not think they had memory gaps and thus did not use the deliberation process to improve their memory, and jurors who controlled deliberation were not always the most accurate in their memories. Finally, those most likely to change their verdict as a result of deliberation were not those who had the least accurate memories, but rather those who had the least confidence in their memories. Copyright © 2002 John Wiley & Sons, Ltd.
Adaptive tracking control for electrically‐driven robots without overparametrization
Authors: Chang Yeong‐Chan
Published: October 2002

This paper addresses the motion tracking control of robot systems actuated by brushed direct current motors in the presence of parametric uncertainties and external disturbances. By using the integrator backstepping technique, two kinds of adaptive control schemes are developed: one requires the measurements of link position, link velocity and armature current for feedback and the other requires only the measurements of link position and armature current for feedback. The developed adaptive controllers guarantee that the resulting closed‐loop system is locally stable, all the states and signals are bounded, and the tracking error can be made as small as possible. The attraction region can be not only arbitrarily preassigned but also explicitly constructed. The main novelty of the developed adaptive control laws is that the number of parameter estimates is exactly equal to the number of unknown parameters throughout the entire electromechanical system. Consequently, the phenomenon of overparametrization, a significant drawback of employing the integrator backstepping technique to treat the control of electrically driven robots in the previous literature, is eliminated in this study. Finally, simulation examples are given to illustrate the tracking performance of electrically driven robot manipulators with the developed adaptive control schemes. Copyright © 2002 John Wiley & Sons, Ltd.
Occupational exposures and the risk of ovarian cancer in Sweden
Authors: Shields Tammy , Gridley Gloria , Moradi Tahere , Adami Johanna , Plato Nils , Dosemeci Mustafa
Published: October 2002

Background

Studies of occupational exposures and ovarian cancer, often limited by few subjects or proportionate mortality data, have yielded inconsistent results.

Methods

Swedish women employed in 1960, 1970, or during both years were followed from 1971 to 1989 using census data linked to nationwide cancer and death registries. A total of 9,591 ovarian cancer cases were identified among 1,670,517 women. Poisson regression was used to estimate the relative risk of ovarian cancer in specific occupational groups and in women exposed to particular occupational exposures defined by job exposure matrices. We lacked data on reproductive factors.

Results

Jobs associated with elevated ovarian cancer rates in this and previous studies include dry cleaning, telegraph and telephone work, paper packaging, and graphic and printing work. In contrast to results of some previous studies, we found that hairdressers and beauticians were not at increased risk of ovarian cancer. Organic dusts, aromatic amines, aliphatic and aromatic hydrocarbons are suggested as specific etiologic agents.

Conclusions

In this large study, we have confirmed some results from smaller studies and identified some new relationships that need to be confirmed elsewhere. Am. J. Ind. Med. 42:200–213, 2002. Published 2002 Wiley‐Liss, Inc.
Pseudodominant inheritance of Langer mesomelic dysplasia caused by a SHOX homeobox missense mutation
Authors: Shears Deborah J. , Guillen‐Navarro Encarna , Sempere‐Miralles Manuel , Domingo‐Jimenez Rosario , Scambler Peter J. , Winter Robin M.
Published: October 2002

We report the clinical and molecular analysis in a consanguineous family in which the skeletal dysplasias Léri‐Weill dyschondrosteosis (LWD) and Langer mesomelic dysplasia (LMD) both segregate. A newborn male and his mother, both with Langer mesomelic dysplasia, are described. A homozygous SHOX homeobox point mutation, C517T, was identified by direct sequencing in the proband and his mother. The same mutation was present in the heterozygous state in the proband's father and in the maternal grandmother, both of whom had features of LWD. This C to T transition is predicted to cause an arginine to cysteine amino acid change in a highly conserved region of the recognition helix of the homeodomain, which may reduce the stability of the interaction between the SHOX protein and its target DNA. In addition, the mutation may disrupt a nuclear localization signal in SHOX. This is the first SHOX point mutation identified in a case of LMD, and the first case in which parent to child transmission of LMD has been described. © 2002 Wiley‐Liss, Inc.
Testing for genetic associations with the PAX gene family in a spina bifida population
Authors: Volcik K.A. , Blanton S.H. , Kruzel M.C. , Townsend I.T. , Tyerman G.H. , Mier R.J. , Northrup H.
Published: October 2002

Neural tube defects (NTDs) are among the most common severely disabling birth defects in the United States, affecting approximately 1–2 of every 1,000 live births. The etiology of NTDs is multifactorial, involving the combined action of both genetic and environmental factors. A nonparametric linkage method, the transmission disequilibrium test (TDT), was utilized to determine if the genes in the PAX family play a role in the formation of NTDs. DNA from 459 spina bifida (SB) patients and their parents (430 mothers and 239 fathers, for a total population of 1,128 subjects) was tested for linkage and association utilizing polymorphic markers from within or very close to the PAX genes of interest. Significant findings were obtained for the following markers: marker locus D20S101 flanking the PAX1 gene (P = 0.019), marker locus D1S228 within the PAX7 gene (P = 0.011), and marker locus D2S110 within the PAX8 gene (P = 0.013). Even though our findings are only mildly significant, given the known expression patterns of the PAX genes in development and the availability of their sequences, we elected to follow up these results by testing these genes directly for mutations utilizing single‐strand conformational analysis (SSCA) and direct sequencing. Multiple variations were detected in each of the PAX genes with significant TDT results; however, these variations were not passed from parent to child in phase with the positively transmitted allele. Therefore, it is unlikely that these variations contribute to susceptibility for SB, but rather are previously unreported polymorphisms. © 2002 Wiley‐Liss, Inc.
Parental origin of normal X chromosomes in Turner syndrome patients with various karyotypes: Implications for the mechanism leading to generation of a 45,X karyotype
Authors: Uematsu Ayumi , Yorifuji Tohru , Muroi Junko , Kawai Masahiko , Mamada Mitsukazu , Kaji Masayuki , Yamanaka Chutaro , Momoi Toru , Nakahata Tatsutoshi
Published: October 2002

The parental origin of the X chromosome of 45,X females has been the subject of many studies, and most of them have shown that the majority (60–80%) of the X chromosomes are maternal in origin. However, studies on the parental origin of normal X chromosomes are relatively limited for Turner syndrome (TS) females with sex chromosome aberrations. In this study, we used PCR‐based typing of highly polymorphic markers and an assay of methylation status of the androgen receptor gene to determine the parental origin of normal X chromosomes in 50 unbiased TS females with a variety of karyotypes. Our results showed a higher paternal meiotic error rate leading to the generation of abnormal sex chromosomes, especially in the case of del(Xp) and abnormal Y chromosomes. Isochromosome Xq and ring/marker X chromosomes, on the other hand, were equally likely the result of both maternal and paternal meiotic errors. A thorough review of previous results, together with our data suggests, that the majority of TS karyotype are caused by paternal meiotic errors that generate abnormal sex chromosomes, and that most 45,X cells are generated by mitotic loss of these abnormal sex chromosomes, resulting in maternal X dominance in these cells. © 2002 Wiley‐Liss, Inc.
Abnormal sterol metabolism in a patient with Antley‐Bixler syndrome and ambiguous genitalia
Authors: Kelley Richard I. , Kratz Lisa E. , Glaser Rivka L. , Netzloff Michael L. , Miller Wolf Linda , Jabs Ethylin W.
Published: October 2002

Antley‐Bixler syndrome (ABS) is a rare multiple anomaly syndrome comprising radiohumeral synostosis, bowed femora, fractures of the long bones, premature fusion of the calvarial sutures, severe midface hypoplasia, proptosis, choanal atresia, and, in some, ambiguous genitalia. Of fewer than 40 patients described to date, most have been sporadic, although reports of parental consanguinity and affected sibs of both sexes suggests autosomal recessive inheritance in some families. Known genetic causes among sporadic cases of ABS or ABS‐like syndromes are missense mutations in the IgII and IgIII regions ofFGFR2, although the assignment of the diagnosis of ABS to such children has been disputed. A third cause of an ABS‐like phenotype is early in utero exposure to fluconazole, an inhibitor of lanosterol 14‐alpha‐demethylase. The fourth proposed cause of ABS is digenic inheritance combining heterozygosity or homozygosity for steroid 21‐hydroxylase deficiency with effects from a second gene at an unknown locus. Because fluconazole is a strong inhibitor of lanosterol 14‐alpha‐demethylase (CYP51), we evaluated sterol metabolism in lymphoblast cell lines from an ABS patient without a knownFGFR2mutation and from a patient with anFGFR2mutation and ABS‐like manifestations. When grown in the absence of cholesterol to stimulate cholesterol biosynthesis, the cells from the ABS patient with ambiguous genitalia but without anFGFR2mutation accumulated markedly increased levels of lanosterol and dihydrolanosterol. Although the abnormal sterol profile suggested a deficiency of lanosterol 14‐alpha‐demethylase, mutational analysis of its gene,CYP51, disclosed no obvious pathogenic mutation in any of its 10 exons or exon‐intron boundaries. Sterol metabolism in lymphoblasts from the phenotypically unaffected mother was normal. Our results suggest that ABS can occur in a patient with an intrinsic defect of cholesterol biosynthesis at the level of lanosterol 14‐alpha‐demethylase, although the genetic nature of the deficiency remains to be determined. © 2002 Wiley‐Liss, Inc.
Interstitial microdeletion of chromosome 1p in two siblings
Authors: Campbell C.G.N. , Wang H. , Hunter G.W.
Published: October 2002

Two half‐siblings are described with what we believe to be the second and third cases identified of the microdeletion, del(1)(p32.1p32.3). Both siblings had a tethered cord and had mental retardation, but otherwise their phenotypic presentations were quite different. The sister had failure to thrive, congenital dysplasia of the hip, absent corpus callosum, Chiari I malformation, and syringomyelia. The brother experienced neonatal seizures secondary to a hemorrhagic stroke. He had an accessory thumb, inguinal hernia, cryptorchidism, urinary reflux, and cholelithiasis. Although these children have only delayed development in common with the previously reported case, they help to further define chromosomal deletions in this area of chromosome 1. As yet, no clear phenotypic picture has emerged. © 2002 Wiley‐Liss, Inc.
Hand and body position during locomotor behavior in the aye‐aye (Daubentonia madagascariensis)
Authors: Krakauer Elissa , Lemelin Pierre , Schmitt Daniel
Published: October 2002

Aye‐ayes (Daubentonia madagascariensis) have unique hands among primates, with extraordinarily long fingers in relation to body size. These long digits may be vulnerable to damage from forces during locomotion, particularly during head‐first descent—a locomotor mode that the aye‐aye utilizes frequently. Previous behavioral studies of aye‐aye locomotion reported that Daubentonia must curl its fingers during horizontal quadrupedalism and/or descent to reduce potential stresses on its long fingers. To test this hypothesis, we examined hand and body position in three captive adult aye‐ayes while they walked quadrupedally on horizontal and oblique branches. Substantial variation in hand position was observed among individuals for each substrate orientation. While hand postures with curled fingers were preferred by one individual during descent, they were not preferred by the other two individuals, contrary to our expectations. Differences in body position were more consistent among all three individuals. The angle of the body relative to the substrate was significantly reduced during descent (8.4°) compared to horizontal locomotion (16.9°). These results suggest that changes in body position, rather than hand position, may help reduce stresses on the digits. A biomechanical model is proposed that demonstrates how a reduction in the body angle in relation to substrate may act to move the center of mass more caudally. This mechanism of moderating loads by altering body position, rather than hand position, may represent an important functional aspect of arboreal locomotion in aye‐ayes and other primates. © 2002 Wiley‐Liss, Inc.
Out of the mouths of baboons: Stress, life history, and dental development in the Awash National Park hybrid zone, Ethiopia
Authors: Dirks Wendy , Reid Donald J. , Jolly Clifford J. , Phillips‐Conroy Jane E. , Brett Frederick L.
Published: October 2002

The techniques of dental histology provide a method for reconstructing much of the life history of an individual, as accentuated increments visible in polarized light microscopy record incidents of physiological stress during the formation of dental tissues. Combined with counts of the normal periodic growth increments, they provide a means of reconstructing the chronology of dental development, age at death, and the ages at which stress occurs. In this study, we determine age at death and reconstruct the chronology of dental development in two male anubis baboons from Uganda and two female baboons from the Awash National Park hybrid zone. For the female baboons, we used the dates of death and rainfall records for the region to determine date of birth, ages at periods of physiological stress, dates at which these stresses occurred, and rainfall amounts for those months.

Ages determined histologically for each specimen are comparable to ages estimated from dental emergence schedules and dental scores for wild baboons. Crown formation times are longer than those reported in radiographic studies of captive yellow baboons. Age at initiation of crown formation is similar to that reported for radiographic studies, but ages at completion of crown formation are consistently later. The pattern of stresses is similar in the two female baboons, suggesting that individual life history intersects with local ecology to produce a pattern of accentuated increments occurring during the weaning process and at the onset of menarche, as well as during the first postweaning dry and rainy periods. Am J Phys Anthropol 118:239–252, 2002. © 2002 Wiley‐Liss, Inc.
Diffuse signal abnormalities in the spinal cord in multiple sclerosis: Direct postmortem in situ magnetic resonance imaging correlated with in vitro high‐resolution magnetic resonance imaging and histopathology
Authors: Bergers Elisabeth , Bot Joost C. J. , van der Valk Paul , Castelijns Jonas A. , Lycklama A Nijeholt Geert J. , Kamphorst Wouter , Polman Chris H. , Blezer Erwin L. A. , Nicolay Klaas , Ravid Rivka , Barkhof Frederik
Published: October 2002

In this study, we compared direct postmortem in situ (whole‐corpse) sagittal spinal cord magnetic resonance imaging (1.5T) of 7 multiple sclerosis cases with targeted high‐resolution in vitro axial magnetic resonance imaging (4.7T) and histopathology. On sagittal in situ magnetic resonance imaging, 1 case had a normal spinal cord, 2 had only focal lesions, 3 had a combination of focal and diffuse abnormalities, and 1 had only diffuse abnormalities. All spinal cords showed abnormalities on high‐resolution magnetic resonance imaging and histopathology, confirming the existence of diffuse cord changes as genuine multiple sclerosis‐related abnormalities while highlighting the limited resolution of in vivo magnetic resonance imaging.
Application of the new McDonald criteria to patients with clinically isolated syndromes suggestive of multiple sclerosis
Authors: Dalton Catherine M. , Brex Peter A. , Miszkiel Katherine A. , Hickman Simon J. , MacManus David G. , Plant Gordon T. , Thompson Alan J. , Miller David H.
Published: October 2002

Traditionally, multiple sclerosis (MS) has been diagnosed on the basis of clinical evidence of dissemination in time and space. Previously, it could not be diagnosed in patients with single clinical episodes of demyelination known as clinically isolated syndromes. New diagnostic criteria from the International Panel of McDonald and colleagues incorporate MRI evidence of dissemination in time and space to allow a diagnosis of MS in patients with clinically isolated syndromes. From clinical and MRI examinations performed prospectively at baseline, 3 months, 1 year, and 3 years of follow‐up, the frequency of developing MS was ascertained by the application of both the new McDonald criteria and the Poser criteria for clinically definite MS. The specificity, sensitivity, positive and negative predictive value, and accuracy of the new criteria for the development of clinically definite MS were assessed. At 3 months, 20 of 95 (21%) patients had MS with the McDonald criteria, whereas only 7 of 95 (7%) had developed clinically definite MS. After 1 year, the corresponding figures were 38 of 79 (48%) and 16 of 79 (20%), and after 3 years, they were 29 of 50 (58%) and 19 of 50 (38%). The development of MS with the new MRI criteria after 1 year had a high sensitivity (83%), specificity (83%), positive predicative value (75%), negative predictive value (89%), and accuracy (83%) for clinically definite MS at 3 years. Use of the new McDonald criteria more than doubled the rate of diagnosis of MS within a year of presentation with a clinically isolated syndrome. The high specificity, positive predictive value, and accuracy of the new criteria for clinically definite MS support their clinical relevance.
Vertebrobasilar stroke as a late complication of a Blalock‐Taussig shunt
Authors: Gailloud Philippe , Hillis Argye , Perler Bruce , Murphy Kieran J.
Published: October 2002

We describe a 39‐year‐old patient with a cerebellar infarct and a history of a tetralogy of Fallot corrected during childhood. This is the first documented case of vertebrobasilar stroke occurring as a late complication of a Blalock‐Taussig shunt followed by total cardiac repair.
Model compound release from DL‐lactide/ε‐caprolactone copolymers and evaluation of specific interactions by molecular modeling
Authors: Rich Jaana , Karjalainen Teija , Ahjopalo Lisbeth , Seppälä Jukka
Published: October 2002

The applicability of poly(DL‐lactide‐co‐ϵ‐caprolactone) copolymers P(DL‐LA/CL) for controlled‐release devices was evaluated. The copolymers of DL‐lactide and ϵ‐caprolactone were polymerized in bulk using Sn(II)octoate as the initiator. The release of three model compounds, theophylline, propranolol hydrochloride, and lidocaine (10 wt%), from high‐lactide content copolymer was studied. The results showed that the copolymer with only minor caprolactone content was not suitable for controlled release of these small‐molecular weight model compounds in matrix‐type devices. A burst in the release rate was observed when the degradation of the matrix replaced diffusion‐controlled release. Increasing the permeation properties of the copolymer matrix through blending and using a different comonomer ratio with an increased caprolactone content were both studied. A release that was more controlled but relatively slow was obtained by using copolyester blends as release matrices. Hydrolytic degradation of the copolymers was also recorded, and the copolymers were found to be very susceptible to hydrolytic chain scission at 37°C. Molecular modeling studies were performed to study the interactions between the theophylline model compound and the homo‐ and copolymers of lactide and ε‐caprolactone units. In agreement with experimental results, the calculations showed increasing interaction between theophylline and the polymer matrix as a function of increasing amount of lactide units. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1–9, 2002
pH‐ and thermal characteristics of graft hydrogels based on chitosan and poly(dimethylsiloxane)
Authors: Kim In Young , Kim Seon Jeong , Shin Mi‐Seon , Lee Young Moo , Shin Dong‐Ic , Kim Sun I.
Published: October 2002

Graft copolymerization of epoxy‐terminated poly(dimethylsiloxane) (PDMS) onto chitosan was reacted without using a catalyst. pH‐sensitive hydrogels were obtained that are based on two different components: a natural polymer and a synthetic polymer. These PDMS substitutents provide the basis for hydrophobic interactions that contribute to the formation of hydrogels. Various graft hydrogels were prepared from different weight ratios of chitosan and PDMS. Swelling behavior of these hydrogels was studied by immersion of the gels in various buffer solution. Photocrosslinked hydrogels exhibited a high equilibrium water content (EWC). Particularly, the sample CP31 of the highest chitosan–PDMS weight ratio showed the highest EWC in time‐dependent, temperature‐dependent, and pH‐dependent swelling behavior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2661–2666, 2002
Transport properties and mechanical behavior of poly(methyl‐phenylsiloxane) membranes as a function of methyl to phenyl groups ratio
Authors: Erdmann E. , Destéfanis H. A. , Abalos R. , Frontini P. M. , Abraham G. A.
Published: October 2002

Membranes based on dimethyl and methyl‐phenylsiloxane were synthesized and then fully characterized. Transport properties and mechanical behavior were determined as a function of different methyl/phenyl group ratios and the effects of these groups on results were established. Membrane transport properties were evaluated from n‐hexane absorption studies. Static tensile stress–strain deformation measurements, stress–hysteresis determination, and stress–relaxation studies were performed to assess the mechanical behavior of these membranes. The results indicate that both physical–mechanical and transport properties are strongly affected by the methyl group content. The increase of the phenyl groups in the polymer chain impairs mechanical properties as a result of which decrease in crosslinking degree and gas permeability due to the diminution in free volume and penetrant solubility. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1624–1633, 2002
Protective flexible coatings on copper by spontaneous polymerization
Authors: Zheng Haipeng , Nainani Kamal , Bell James P.
Published: October 2002

Spontaneous polymerization (S‐Poly) is a novel process for forming protective polymer coatings on metals. The S‐Poly mechanism on copper is discussed for one typical monomer system. Poly(ethylene glycol) ethyl ether methacrylate (EEM), a flexible monomer, was first introduced into a styrene/N‐phenyl maleimide system that we had used for aluminum and steel. The effects of EEM on the composition, apparent molecular weight, thermal properties, and other properties of the coatings were studied with reflectance Fourier transform infrared, gel permeation chromatography, differential scanning calorimetry, and water‐uptake and adhesion experiments. N‐(4‐Fluorophenyl) maleimide (4FMI), a strongly hydrophobic monomer, was further incorporated into the EEM copolymer for improved water impermeability. The resultant coatings, which included EEM and 4FMI units, showed good bonding strength to copper and better ductility and protective properties than other coatings in both corrosion and pinhole tests. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1749–1757, 2002
An examination of the shear‐thickening behavior of high molecular weight polymers dissolved in low‐viscosity Newtonian solvents
Authors: Edwards B. J. , Keffer D. J. , Reneau C. W.
Published: October 2002

The anomaly of shear thickening at high shear rates can be observed under certain conditions for high molecular weight polymers dissolved in low‐viscosity Newtonian solvents despite the fact that shear‐thinning behavior is considered the norm for these fluids. The nature of the shear‐thickening region of the flow curve is examined herein through the application of a recent rheological model that has the capability of quantifying not only the rheological properties of the material, but its internal microstructural state as well. The results of this examination provide a self‐consistent explanation of the full flow characterization of this anomalous behavior, including both rheological and optical experimental measurements. The results presented herein suggest that the shear‐thickening behavior is actually caused by the destruction of structures formed during shear at lower shear rates, not by their formation, as previously assumed. The linear birefringence and linear dichroism observed experimentally in correlation with the shear‐thickening behavior are well described by the rheological model and give predictions in line with experimental measurements. Furthermore, quantitative predictions are made for rheological characteristic functions, such as the first and second normal‐stress coefficients, for which experimental measurements for these solutions have not yet been made. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1714–1735, 2002
Immobilization of a cyclodextrin glucanotransferase (CGTase) onto polyethylene film with a carboxylic acid group and production of cyclodextrins from corn starch using CGTase‐immobilized PE film
Authors: Choi Seong‐Ho , Kim Min‐Seok , Ryoo Jae Jeong , Lee Kwang‐Pill , Shin Hyun‐Dong , Kim Sun‐Hwa , Lee Yong‐Hyun
Published: October 2002

Carboxylic acid groups were introduced onto polyethylene (PE) film by radiation‐induced graft copolymerization. Subsequently, the clodextrin glucanotransferase (CGTase) was immobilized on the PE film with a carboxylic acid group. The activity of the immobilized CGTase on PE film was in the range of 0.40–1.04 U/cm2 per min. The production of cyclodextrins (CDs) from corn starch was examined using the CGTase‐immobilized PE film. The production ratios of CDs using CGTase‐immobilized PE film was in the following order: α–CD > β–CD > γ–CD. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2451–2457, 2002
Permeation of mixtures of organic liquids through polymeric membranes: Role of liquid–liquid interactions
Authors: Perron Gérald , Desnoyers Jacques E. , Lara Jaime
Published: October 2002

The permeation of pure organic liquids and mixtures of organic liquids through commercial butyl, neoprene, and nitrile membranes was studied using dynamic material deformation (swelling) and permeation techniques. The derived parameters, the breakthrough time (tBT), steady‐state permeation rate (SSPR), and initial swelling rate (SR), show deviations from additivity for the mixtures, based on the parameters of the pure liquids on a mol fraction basis. In the majority of cases for the three membranes examined, the deviations are independent of the nature of the membranes, and the signs of the deviations for tBT are opposite to those for SSPR or SR, provided that the membranes are not degraded by one of the solvents. An approach that considers only solvent–solvent interactions based on the enthalpy of mixing was used to predict deviations for mixtures. For mixtures where the enthalpy of mixing is large and exothermic, the permeation of the mixture is less than expected, while for systems where the enthalpy of mixing is large and endothermic, the permeation is larger than expected. A simple semiempirical model predicts the sign and magnitude of the permeation of 73% of the system–permeation property combinations investigated, which show significant deviations from ideality. It is interesting to note that the wrong predictions are for systems where the predictions are positive, that is, for SSPR and SR rates with endothermic systems and for tBT with exothermic systems. The exceptions also seem to be for systems that correspond to materials having a high resistance to one of the solvents and a very low resistance to the other solvent. Examples of ternary–mixture permeation data are also given and show that, even if two of the pure components do not permeate through a membrane, the membrane will offer little protection if the third component shows a high affinity for the membrane and if the enthalpies of mixing of this component with the other liquids are endothermic. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 195–215, 2002
Some sorption characteristics of poly(trimethylene terephthalate) with disperse dyes
Authors: Yang Yiqi , Brown Houston , Li Shiqi
Published: October 2002

Sorption characteristics, such as sorption kinetics and isotherms, relation between dye sorption and shade development of poly(trimethylene terephthalate) (PTT) and their comparison with poly(ethylene terephthalate) (PET), were reported. Results from two different dyeing rate studies, dyeing rate under constant temperature and under changing temperature, were examined to obtain the common rate constants, and to obtain information for the design of dyeing temperature profile and holding time. Rate constants of PTT were compared with that of PET. Sorption isotherms of disperse dyes on PTT were also studied. Both Nernst and Langmuir models were examined. The dye uptake ability of PTT was compared with PET. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 223–229, 2002
Functional gliding spaces of the dorsal side of the human hand
Authors: Thurmüller Petra , Schubert Markus , Bade Holger , Notermans Hans‐Peter , Knifka Jutta , Koebke Jürgen
Published: October 2002

The clinical and functional importance of gliding spaces of the hand (e.g., their role in the spread of infection or as a consideration in reconstructive surgery) has been repeatedly emphasized. However, only a few studies have provided details regarding the connective tissue spaces in the metacarpal region of the dorsal side of the human hand. The aim of the present study was to analyze the morphology and elucidate the anatomic relation of functional gliding spaces in the metacarpal region on the dorsal side of the human hand in order to provide a better understanding of function, and of clinical disorders and their treatment. To delineate these spaces we used a plastic (Acrifix 90®) injection method. Twenty fixed and unfixed cadaver hands were subcutaneously injected with Acrifix 90® (a methacrylate) into the metacarpophalangeal transitional region and into the tendon sheaths of the extensor muscles. Different colors were used to distinguish one injected plastic solution from another. The spreading pattern of the injected medium was analyzed by careful dissection. To delineate the exact bordering structures and the topography of the injected spaces, two hands were plastinated using the E12/E6 technique (von Hagens et al., Anat Embryol 1987;175:411–421), and one hand was injected and embedded in Technovit 7100® for histological investigations. Injecting the plastic into the metacarpophalangeal transitional region of fingers II–IV in a disto‐proximal direction, the solution spreads along the surface of the separate extensor tendons. It then coalesces 1–2 cm proximal to the injection points to form a continuous plastic plate, which protrudes between and on top of the previous injected tendon sheaths. In no case was a communication between the paratendinous tissue and the tendon sheaths observed. Laterally, the injected solution is delimited at the radial side of the extensor tendon of the second finger and at the ulnar side of the extensor tendon of the fourth finger. Using the described technique at the fifth finger yields a plastic plate that extends from the injection point to the tendon sheath. However, in two specimens a connection between the plastic injected into the tendon sheath of the fifth finger, and the distal injected solution was observed. Anat Rec 267:242–251, 2002. © 2002 Wiley‐Liss, Inc.
Statistical quality control in archaeological survey
Authors: Almagro‐Gorbea Martín , Alonso Pablo , Benito José Enrique , Martín Ana M. , Valencia José Luis
Published: October 2002

This paper proposes a statistical method to establish the quality of the results in archaeological survey. A random sample, a simple statistical operation and the use of standard tables, adapted to this kind of work, allow us to determine when the archaeological prospection has an acceptable quality or not. This kind of investigation has never been undertaken in archaeology, but it will be of the most suitable use in the future to know the reliability of the results for scientific or heritage purposes. Copyright © 2002 John Wiley & Sons, Ltd.