bluuebunny/crossref_metadata_2025 huggingface dataset:
Color associations with different building types: An experimental study on American college students
Authors: Kaya Naz , Crosby Melanie
Published: December 2005

This study examines individuals' color associations with different building types (i.e., residences, schools, official buildings, hospitals, shopping malls, entertainment buildings, restaurants, hotels, factories, and religious buildings) and the reasons given behind their color choices. Ninety‐eight college students at a public institution in the southeast region of the United States participated in the study. Results indicate that color associations seem to be based on individual and emotional aspects where previous knowledge and experience with a particular building type play an important role. The reasons for color‐building associations are discussed and future research areas are suggested. © 2005 Wiley Periodicals, Inc. Col Res Appl, 31: 67–71, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20174
Surface reflectance modeling of real objects with interreflections for augmented virtuality
Authors: Machida Takashi , Yokoya Naokazu , Takemura Haruo
Published: December 2005

In mixed reality, especially in augmented virtuality, in which real objects are virtualized, it is important to estimate object surface reflectance properties in order to render the objects under arbitrary illumination conditions. Although several methods have been explored, faithfully estimating surface reflectance parameters for complex objects having nonuniform surface reflectance properties or interreflections remains difficult. This article describes a new method for densely estimating the nonuniform surface reflectance properties of real objects constructed of convex and concave surfaces with interreflections. Registered range and surface color texture images are obtained using a laser rangefinder. In the proposed method, light source positions are first determined in order to obtain color images for discriminating diffuse and specular reflection components considering the object geometry. Surface reflectance parameters are then estimated based on radiosity and the Torrance–Sparrow model. The usefulness of the proposed method is shown experimentally. © 2005 Wiley Periodicals, Inc. Col Res Appl, 31, 38–47, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20184
Diabetes preventive gluten‐free diet decreases the number of caecal bacteria in non‐obese diabetic mice
Authors: Hansen Axel Kornerup , Ling Fengjun , Kaas Anne , Funda David P. , Farlov Helene , Buschard Karsten
Published: December 2005

Background

A gluten‐free diet reduces the incidence of diabetes mellitus in non‐obese diabetic (NOD) mice, but the mechanism is not known. The aim of this study was to examine the possible influence of the diet on the caecal bacterial flora, which may affect the intestinal physiology and mediate disease prevention.

Methods

Two groups of NOD mice from the age of 3 weeks were fed either a gluten‐free diet or a standard diet. Each diabetic mouse, when diagnosed, along with a non‐diabetic mouse from the same diet group and two non‐diabetic mice from the alternate diet group were euthanized and sampled for classical bacteriological examination.

Results

Nine out of 19 (47%) standard‐fed mice and 1 out of 19 (5%) gluten‐free‐fed mice developed diabetes (p < 0.01). Mice on the gluten‐free diet had significantly fewer aerobically (p < 0.01) and microaerophilically (p < 0.001) cultivated bacteria in their intestines than standard‐fed mice. Non‐diabetic mice also had significantly fewer microa erophilic and anaerobic bacteria than diabetic mice (p < 0.05). These differences were primarily due to a difference in the Gram‐positive flora.

Conclusions

The gluten‐free diet compared to the standard diet both qualitatively and quantitatively substantially altered the composition of the caecal bacterial flora in NOD mice. Although Gram‐positive bacteria might influence the beta cells through certain digestive products, it is more likely to assume that any effect on diabetes incidence is immunological. Copyright © 2005 John Wiley & Sons, Ltd.
The relevance of international consortia in studies on the pathogenesis of type 1 diabetes: the role of ET1DGN
Authors: Pociot Flemming
Published: December 2005

The Type 1 Diabetes Genetics Consortium (T1DGC), funded September 2002, is a collaborative effort to develop resources for the purpose of identifying risk genes for type 1 diabetes. One of the aims is to establish a renewable resource of DNA on 2500 affected sib‐pair families. Regional networks have been established and in continental Europe, the European Type 1 Diabetes Genetics Network (ET1DGN) is responsible for identifying and collecting families. Most European countries have shown interest in this study and many have started recruiting families. The consortium is open to participation and there are several ways one can participate as a member of the consortium. ET1DGN suggests going beyond the tasks of T1DGC and establishing a well‐organized network for additional and future studies in Europe. Copyright © 2005 John Wiley & Sons, Ltd.
Change in the shape and density of dendritic spines caused by overexpression of acidic calponin in cultured hippocampal neurons
Authors: Rami Guillaume , Caillard Olivier , Medina Igor , Pellegrino Christophe , Fattoum Abdellatif , Ben‐Ari Yezekiel , Ferhat Lotfi
Published: December 2005

Dendritic spines are morphing structures believed to provide a cellular substrate for synaptic plasticity. It has been suggested that the actin cytoskeleton is the target of molecular mechanisms regulating spine morphology. Here we hypothesized that acidic calponin, an actin‐binding protein, is one of the key regulators of actin filaments during spine plasticity. Our data showed that the overexpression of acidic calponin‐GFP (green fluorescent protein) in primary cultures of rat hippocampal neurons causes an elongation of spines and an increase of their density as compared with those of GFP‐expressing neurons. These effects required the actin‐binding domains of acidic calponin. The close apposition of the presynatic marker synaptophysin to these long spines and the presence of specific postsynaptic markers actin, PSD‐95, NR1, and GluR1 suggested the existence of functional excitatory synaptic contacts. Indeed, electrophysiological data showed that the postsynaptic overexpression of acidic calponin enhanced the frequency of miniature excitatory postsynaptic currents as compared with that of GFP‐expressing neurons, but did not affect their properties such as amplitude, rise time, and half width. Studies in heterologous cells revealed that acidic calponin reorganized the actin filaments and stabilized them. Taken together, these findings show that acidic calponin regulates dendritic spine morphology and density, likely via regulation of the actin cytoskeleton reorganization and dynamic. Furthermore, the acidic calponin‐induced spines are able to establish functional glutamatergic synapses. Such data suggest that acidic calponin is a key factor in the regulation of spine plasticity and synaptic activity. © 2005 Wiley‐Liss, Inc.
Intracranial therapy of glioblastoma with the fusion protein DTIL13 in immunodeficient mice
Authors: Rustamzadeh Edward , Hall Walter A. , Todhunter Deborah A. , Low Walter C. , Liu Haiying , Panoskaltsis‐Mortari Angela , Vallera Daniel A.
Published: December 2005

A fusion protein consisting of human interleukin‐13 and the first 389 amino acids of diphtheria toxin was assembled in order to target human glioblastoma cell lines in a murine intracranial model. In vitro studies to determine specificity indicated that the protein called DTIL13 was highly selective for human glioblastoma. In vivo, the maximum tolerated dose of DTIL13 was 1 μg/injection given every other day and repeated for 3 days. Doses that exceeded this amount resulted in weight loss and liver damage as determined by histology and enzyme assay. Experiments in IL‐4 receptor knockout mice revealed that liver toxicity was receptor‐related. This same dose given to nude mice with established U373 MG brain tumors resulted in significant reductions in tumor volume and significantly prolonged survival (p < 0.0001). Magnetic resonance imaging (MRI) proved to be extremely useful in (i) determining the ability of DTIL13 to reduce tumor size and (ii) for studying toxicity since diffusion‐weighted and gradient echo‐weighted MRI revealed that vascular leak syndrome was not a limiting toxicity at this dose. These results suggest that DTIL13 is as effective in an intracranial rodent model as it was in a flank model in previous studies and that DTIL13 might be an effective treatment for glioblastoma multiforme. © 2005 Wiley‐Liss, Inc.
Functional variants in the promoter of interleukin‐1β are associated with an increased risk of breast cancer: A case‐control analysis in a Chinese population
Authors: Liu Jiyong , Zhai Xiangjun , Jin Guangfu , Hu Zhibin , Wang Shui , Wang Xuechen , Qin Jianwei , Gao Jun , Ma Hongxia , Wang Xinru , Wei Qingyi , Shen Hongbing
Published: December 2005

Interleukin 1β (IL‐1β) is a multifunctional cytokine that upregulates the inflammatory response, and participates in carcinogenesis, malignant transformation, tumor growth, invasion and metastasis. Two potentially functional polymorphisms (T‐31C and C‐511T) in the IL‐1β gene promoter were suggested to be correlated with alteration of IL‐1β expression and therefore may be associated with cancer risk. To test the hypothesis that these 2 polymorphisms are associated with risk of breast cancer, we performed a case‐control study of 365 breast cancer cases, 270 patients with benign breast diseases (BBD) and 631 cancer‐free controls in a Chinese population. Multivariate logistic regression analyses revealed that increased risk of breast cancer was associated with IL‐1β‐31C variant genotypes [adjusted odds ratio (OR) = 1.28 and 95% confidence interval (CI) = 0.91–1.80 for ‐31CT and 1.72 (95% CI = 1.16‐2.54) for ‐31CC], compared with the ‐31TT genotype. Similarly, IL‐1β‐511T variant genotypes were also associated with increased risk of breast cancer (adjusted OR = 1.20, 95% CI = 0.86–1.67 for ‐511CT and adjusted OR = 1.74, 95% CI = 1.18–2.56 for ‐511TT), compared with the ‐511CC genotype. Furthermore, cancer risks associated with IL‐1βT‐31C variant genotypes were more evident in older women, postmenopausal women and individuals with a later menarche age. Interestingly, although we did not find significant associations of these 2 variants with cancer risk when compared with the BBD patients, a 1.27‐fold (95% CI = 1.01–1.60) increased risk was observed with the ‐31C‐511T common haplotype. These findings indicate that these 2 IL‐1β promoter variants may contribute to risk of developing breast cancer in the Chinese population. © 2005 Wiley‐Liss, Inc.
The effect of box shape on the dynamic properties of proteins simulated under periodic boundary conditions
Authors: Wassenaar Tsjerk A. , Mark Alan E.
Published: December 2005

The effect of the box shape on the dynamic behavior of proteins simulated under periodic boundary conditions is evaluated. In particular, the influence of simulation boxes defined by the near‐densest lattice packing (NDLP) in conjunction with rotational constraints is compared to that of standard box types without these constraints. Three different proteins of varying size, shape, and secondary structure content were examined in the study. The statistical significance of differences in RMSD, radius of gyration, solvent‐accessible surface, number of hydrogen bonds, and secondary structure content between proteins, box types, and the application or not of rotational constraints has been assessed. Furthermore, the differences in the collective modes for each protein between different boxes and the application or not of rotational constraints have been examined. In total 105 simulations were performed, and the results compared using a three‐way multivariate analysis of variance (MANOVA) for properties derived from the trajectories and a three‐way univariate analysis of variance (ANOVA) for collective modes. It is shown that application of roto‐translational constraints does not have a statistically significant effect on the results obtained from the different simulations. However, the choice of simulation box was found to have a small (5–10%), but statistically significant effect on the behavior of two of the three proteins included in the study. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 316–325, 2006
Plasma membrane calcium ATPase is concentrated in the head of sea urchin spermatozoa
Authors: Gunaratne Herath Jayantha , Neill Anna T. , Vacquier Victor D.
Published: December 2005

Plasma membrane Ca2+ATPases (PMCAs) export Ca2+ from cells in a highly regulated manner, providing fine‐tuning to the maintenance of intracellular Ca2+ concentrations. There are few studies of PMCAs in spermatozoa, which is surprising considering the importance of this enzyme in all cell types. Here we describe the primary structure and localization of the PMCA of sea urchin spermatozoa (suPMCA). The suPMCA is 1,154 amino acids and has 56% identity and 76% similarity to all 4 human PMCA isoforms. The suPMCA shares the features of a typical PMCA, including domains for calmodulin binding, ATP binding, ATPase phosphorylation, and 10 putative transmembrane segments with two large cytoplasmic loops. Southern blots show that suPMCA is a single copy gene. Treatment of live sea urchin sperm with the PMCA inhibitor, 5‐(‐6)‐carboxyeosin, results in elevations of intracellular Ca2+ and loss of flagellar motility. Immunoblotting and immunoflorescence show that suPMCA is concentrated in the sperm head plasma membrane. In previous work, we showed that a plasma membrane K+ dependent Na+/Ca2+ exchanger (suNCKX), which also keeps Ca2+ low in these cells, is concentrated in the sperm flagellum. Thus, the sperm head and flagellum localize different gene products, both functioning to keep intracellular Ca2+ low, while the sperm swims in seawater containing 10 mM Ca2+. J. Cell. Physiol. 207: 413–419, 2006. © 2005 Wiley‐Liss, Inc.
Heritability and heterochrony of polychromatism in a Lake Victoria Cichlid fish: stepping stones for speciation?
Authors: Maan Martine E. , Haesler Marcel P. , Seehausen Ole , Van Alphen Jacques J.M.
Published: December 2005

In many haplochromine cichlid fish, male nuptial coloration is subject to female mate choice and plays a central role in the evolution of reproductive isolation between incipient species. Intraspecific variation in male coloration may serve as a target for diversifying sexual selection and provide a starting point for species divergence. Here, we investigated a polychromatism in Neochromis omnicaeruleus, a haplochromine from Lake Victoria, East‐Africa. In this species, male coloration ranges from skyblue to yellow‐red and females are grey‐blue to yellow. We found that both genetic and environmental factors influence the expression of these colours during individual development. In a natural population, we found that male colour was associated with size and sexual maturity: yellow males were smaller than blue males and tended to be sexually immature. In females, size and maturity did not differ between colour types. Laboratory crosses revealed that there is a heritable component to the observed colour variation: yellow parents produced more yellow offspring than blue parents. Together with repeated aquarium observations of yellow individuals that gradually become blue, these data suggest that yellow males change to blue as they approach sexual maturity, and that the occurrence and timing of this transition is influenced by both environmental and genetic effects. The significance of this mechanism of colour expression as a possible target for divergent selection remains to be evaluated. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2005 Wiley‐Liss, Inc.
Neural crest cells and patterning of the mammalian dentition
Authors: Cobourne Martyn T. , Mitsiadis Thimios
Published: December 2005

The mammalian dentition is composed of serial groups of teeth, each with a distinctive crown and root morphology, highly adapted to its particular masticatory function. In the embryo, generation of individual teeth within the jaws relies upon interactions between ectoderm of the first branchial arch and the neural crest‐derived ectomesenchymal cells that migrate into this region from their site of origin along the neural axis. Classic tissue recombination experiments have provided evidence of an essential role of the ectoderm in initiating tooth development; however, the underlying ectomesenchyme rapidly acquires dominance in establishing shape. A key question is how these cells acquire this positional information. One theory suggests that ectomesenchymal cells are pre‐patterned with respect to shape generation. Alternatively, this cell population acquires positional information within the first branchial arch itself, following migration. Recent molecular evidence suggests a high degree of plasticity within these ectomesenchymal cells. In particular, signalling molecules within the ectoderm exert a time‐dependent influence upon the ectomesenchyme by establishing specific domains of homeobox gene expression. Initially, these ectomesenchymal cells are plastic and able to respond to signalling from the ectoderm, however, this plasticity is rapidly lost and pattern information becomes fixed. Therefore, in the first branchial arch, local regulation between the ectoderm and neural crest‐derived ectomesenchyme is crucial in establishing the appropriate tooth shape in the correct region of the jaw. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2005 Wiley‐Liss, Inc.
Evolutionary genetics of vertebrate tissue mineralization: the origin and evolution of the secretory calcium‐binding phosphoprotein family
Authors: Kawasaki Kazuhiko , Weiss Kenneth M.
Published: December 2005

Three principal mineralized tissues are present in teeth; a highly mineralized surface layer (enamel or enameloid), body dentin, and basal bone. Similar tissues have been identified in the dermal skeleton of Paleozoic jawless vertebrates, suggesting their ancient origin. These dental tissues form on protein matrix and their mineralization is controlled by distinctive proteins. We have shown that many secretory calcium‐binding phosphoproteins (SCPPs) are involved in tetrapod tissue mineralization. These SCPPs all originated from the common ancestral geneSPARCL1(secreted protein, acidic, cysteine‐rich like 1) that initially arose fromSPARC. The SCPP family also includes a bird eggshell matrix protein, mammalian milk casein, and salivary proteins. The eggshell SCPP plays crucial roles in rigid eggshell production, milk SCPPs in efficient lactation and in the evolution of complex dentition, and salivary SCPPs in maintaining tooth integrity. A comparative analysis of the mammalian, avian, and amphibian genomes revealed a tandem duplication history of the SCPP genes in tetrapods. Although these tetrapod SCPP genes are fewer in teleost genomes, independent parallel duplication has created distinct SCPP genes in this lineage. These teleost SCPPs are also used for enameloid and dentin mineralization, implying essential roles of SCPPs for dental tissue mineralization in osteichthyans. However, the SCPPs used for tetrapod enamel and teleost enameloid, as well as tetrapod dentin and teleost dentin, are all different. Thus, the evolution of vertebrate mineralized tissues seems to be explained by phenogenetic drift: while mineralized tissues are retained during vertebrate evolution, the underlying genetic basis has extensively drifted.J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2005 Wiley‐Liss, Inc.
The last excluded case of Dirac's map‐color theorem for choosability
Authors: Král' Daniel , S̆krekovski Riste
Published: December 2005

In 1890, Heawood established the upper bound $H ( \varepsilon )= \left \lfloor 7+\sqrt {24\varepsilon +1}/{2}\right \rfloor$ on the chromatic number of every graph embedded on a surface of Euler genus ε ≥ 1. Almost 80 years later, the bound was shown to be tight by Ringel and Youngs. These two results have became known under the name of the Map‐Color Theorem. In 1956, Dirac refined this by showing that the upper bound H(ε) is obtained only if a graph G contains KHε as a subgraph except for three surfaces. Albertson and Hutchinson settled these excluded cases in 1979. This result is nowadays known as Dirac's Map‐Color Theorem. Böhme, Mohar, and Stiebitz extended Dirac's Map‐Color Theorem to the case of choosability by showing that G is (H(ε) − 1)‐choosable unless G contains KH(ε) as a subgraph for ε ≥ 1 and ε ≠ 3. In the present paper, we settle the excluded case of ε = 3. © 2005 Wiley Periodicals, Inc. J Graph Theory 51: 319–354, 2006
Tropical ice core records: evidence for asynchronous glaciation on Milankovitch timescales
Authors: Thompson Lonnie G. , Davis Mary E. , Mosley‐Thompson Ellen , Lin Ping‐Nan , Henderson Keith A. , Mashiotta Tracy A.
Published: December 2005

Over the last 28 years ice core records have been systematically recovered from ten high‐elevation ice fields, nine of which are located in the low latitudes. Each core has provided new information about the regional climate and environmental change, and together their records challenge existing paradigms about the Earth's climate system. When viewed collectively, these ice core histories provide compelling evidence that the growth (glaciation) and decay (deglaciation) of large ice fields in the lower latitudes are often asynchronous, both between the hemispheres and with high latitude glaciation that occurs on Milankovitch timescales. Although stable isotopic records suggest that global‐scale cooling occurred during the Last Glacial Stage (LGS), we contend that precipitation is the primary driver of glaciation in the low latitudes. This is consistent with the time‐transgressive nature of precession‐driven changes in insolation (and hence precipitation) such that glaciers advance/retreat in the tropics north of the equator while glaciers retreat/advance in the tropics south of the equator. Thus, the coeval inter‐hemispheric retreat of glaciers in the 20th century and the beginning of the 21st century is atypical. Copyright © 2005 John Wiley & Sons, Ltd.
Late Quaternary deglacial history of the Mérida Andes, Venezuela
Authors: Stansell Nathan D. , Abbott Mark B. , Polissar Pratigya J. , Wolfe Alexander P. , Bezada Maximiliano , Rull Valentí
Published: December 2005

Radiocarbon‐dated sediment cores from seven lakes and two bogs spanning the Cordillera de Mérida in the Venezuelan Andes were used to identify and date the regional history of late Pleistocene and Holocene glacial activity. Coring sites were selected at different elevations across a pronounced rain shadow from southeast (wet) to northwest (dry). Sediment lithostratigraphy and magnetic susceptibility, in conjunction with AMS radiocarbon dates on macrofossils and charcoal, were used to constrain deglaciation. The local expression of the Last Glacial Maximum occurred between 22 750 and 19 960 cal. yr BP. On the wetter southeastern side of the Cordillera de Mérida, glaciers had significantly retreated by 15 700 cal. yr BP, followed by several minor glacial advances and retreats between 14 850 and 13 830 cal. yr BP. At least one major glacial readvance occurred between 13 830 and 10 000 cal. yr BP in the wetter southeastern sector of the region. The drier northwest side of the Cordillera de Mérida records initial glacial retreat by 14 240 cal. yr BP. Multiple sites on both sides of the Mérida Andes record a further phase of extensive deglaciation approximately 10 000 cal. yr BP. However, the north‐northwest facing Mucubají catchment remained partially glaciated until ca. 6000 cal. yr BP. Deglacial ages from the Venezuelan Andes are consistently younger than those reported from the Southern Hemisphere Andes, suggesting an inter‐hemispheric deglacial lag in the northern tropics of the order of two thousand years. Copyright © 2005 John Wiley & Sons, Ltd.
Reconstruction of glacier equilibrium‐line altitudes for the Last Glacial Maximum on the High Plain of Bogotá, Eastern Cordillera, Colombia: climatic and topographic implications
Authors: Mark Bryan G. , Helmens Karin F.
Published: December 2005

The High Plain of Bogotá in the Andes of Colombia provides an exceptionally detailed record of glaciation. A two‐stage Last Glacial Maximum (LGM) is noted in Bogotá; the older stage (max) presents an opportunity to reconstruct individual valley glaciers and explore spatial patterns. Well‐mapped geomorphic features on topographic base maps permit the reconstruction of 23 palaeoglacier surfaces. Glacier extent varies across the region, with lower altitudes reached farther to the east. Equilibrium line altitudes (ELAs) are reconstructed using the area–altitude balance ratio (AABR) method, with BRs in three groups reflecting the W–E gradient in glacier extent and selected by minimising variation from group means. Average LGM ELA for all palaeoglaciers is 3488 m with a standard deviation of 182 m. The average lowering in ELA from LGM to modern of ca. 1300 m is best explained by a considerable drop in temperature. Significant intra‐regional variance in LGM ELA can be ascribed to topography and its influence on precipitation and/or glacier form, with lower headwall elevations being correlated to larger accumulation areas. Copyright © 2005 John Wiley & Sons, Ltd.
Delta progradation and Neoglaciation, Laguna Parón, Cordillera Blanca, Peru
Authors: Seltzer Geoffrey O. , Rodbell Donald T.
Published: December 2005

The history of Holocene glaciation serves as an important record of glacier mass balance and, therefore, of climatic change. The moraine record of Holocene glaciation in the tropical Andes, however, is fragmentary and poorly dated. In contrast, increases in the rate of accumulation of inorganic sediment in glacier‐fed lakes have been linked to periods of Neoglaciation in many mountain regions. The interpretation of such a record of Neoglaciation from sediment cores in glacier‐fed lakes in the tropical Andes can provide the continuity and chronologic control that is lacking in the existing moraine record. Unusual exposures of glacial lacustrine sediment in the Cordillera Blanca, Peru, provide a rare opportunity to assess the link between climatic change, glaciation, and lacustrine sedimentation.

Intentional lowering of water levels in Laguna Parón (9°S, 77°44′ W, 4200 m a.s.l.) in 1985 resulted in the incision and exposure of at least 20 m of deltaic deposits at the eastern end of the lake. Three deltaic units can be identified: horizontal topset beds, steeply dipping and deformed foreset beds, and horizontally laminated fine‐grained sediment. Six radiocarbon ages ranging from 1800 ± 210 to 465 ± 95 14C yr BP on wood indicate that the average rate of delta progradation in the late Holocene has been approximately 290 m per 1000 yr. The lake formed during deglaciation at least 10 000 yr ago and if such a rate of progradation of the delta had prevailed over the entire Holocene, then the delta would be at least three times as extensive as it is today. Thus the rate of delta progradation has varied significantly over the Holocene. We suggest that the rate of delta progradation was at least three times greater when glaciers were in advanced positions. These positions are clearly delimited by Neoglacial moraines, which are within 1–2 km of the exposures studied and within 1 km of modern ice limits. The most recent increase in the rate of delta progradation is evidenced by an increase in sedimentation rate ca. 575 ± 90 14C yr BP, coincident with the onset of the Little Ice Age. Copyright © 2005 John Wiley & Sons, Ltd.
The Last Glacial Maximum: stability and change in a western Amazonian cloud forest
Authors: Urrego Dunia H. , Silman Miles R. , Bush Mark B.
Published: December 2005

The climatic and vegetation history of a western Amazonian cloud forest is documented in a continuous pollen record spanning the full last glacial period between 43.5 and 22k  cal. yr BP. The chronology for this record is based on eight radiocarbon dates yielding a low‐resolution pollen analysis for the region. A bioclimatic envelope model was generated on the basis of modern altitudinal distributions and the pollen data, which produced a glacial palaeotemperature estimate of ca. −5°C relative to present. Palaeoecological evidence of continuous moist cloud forest cover in the basin indicates that western Amazonian forests were not fragmented during the LGM. This evidence supports wet conditions in western Amazonia at the LGM and further refutes hypotheses of Amazonian aridity during the last ca. 44k cal. yr BP. Copyright © 2005 John Wiley & Sons, Ltd.
Contrasting pollen histories of MIS 5e and the Holocene from Lake Titicaca (Bolivia/Peru)
Authors: Hanselman Jennifer A. , Gosling William D. , Paduano Gina M. , Bush Mark B.
Published: December 2005

Two long sediment records (cores LTO1‐2B and LT01‐3B) from Lake Titicaca, Bolivia/Peru, are compared with a previously analysed Holocene record from this lake (core NE98‐1PC). The Holocene records of LT01‐2B and NE98‐1PC are similar. There are striking differences, however, between the MIS 5e sections of the long cores and the Holocene records. In these records, temperature is probably the dominant parameter that determines the total fossil pollen concentration and is used to time the onset and termination of deglaciation. In contrast, the relative and absolute abundance of specific taxa (e.g. Polylepis/Acaena, Chenopodiaceae) are indicators of relative moisture availability. Although the Holocene contains a period of aridity between ca. 8000 cal. yr BP and 4300 cal. yr BP, it is a minor event compared with the more extreme aridity of MIS 5e. Core LT01‐3B showed similar trends during MIS 5e when compared to LT01‐2B, as did NE98‐1PC when comparing Holocene records. MIS 5e and the Holocene are markedly different interglacials, depicted by shifts in pollen concentration and taxa representation over time. Copyright © 2005 John Wiley & Sons, Ltd.
Equilibrium‐line altitudes during the Last Glacial Maximum across the Brooks Range, Alaska
Authors: Balascio Nicholas L. , Kaufman Darrell S. , Manley William F.
Published: December 2005

Equilibrium‐line altitudes (ELAs) were estimated for 383 reconstructed glaciers across the Brooks Range, northern Alaska, to investigate their regional pattern during the Last Glacial Maximum (LGM). Glacier outlines were delimited based on published field mapping and the original interpretations of aerial photographs. Glacier margins were digitised from 1:63 360‐scale maps into a geographic information system (GIS) with a digital elevation model on a 60‐m grid. ELAs were calculated for each reconstructed glacier using the accumulation area ratio method (AAR = 0.58). The analysis was restricted to relatively simple cirque and valley glaciers that deposited clearly identifiable LGM moraines, and that did not merge with the complex transection glacier ice that filled most troughs of the range. The glaciers used in this analysis had areas ranging from 0.14 to 120 km2. Their ELAs rose from 470 m a.s.l. in the western Brooks Range to 1860 m a.s.l. in the east, over a distance of 1000 km. The ELAs were fitted with a third‐order polynomial trend surface to model their distribution across the range, and to investigate the source of local‐scale variations. The trend surface lowers toward the west and south, similar to previously derived trends based on glaciation thresholds. In addition, ELAs in the northeastern part of the range lower northward toward the Beaufort Sea, which has not been reported as strongly in other studies. Modern glacier ELAs also lower toward the southwest. The depression of LGM ELAs from modern glacier ELAs is greatest in the central Brooks Range (a maximum of 700 m), and decreases to the east (200 m). The regional pattern of LGM ELAs points to the primary source of moisture from the North Pacific, as it is today. The unexpected trend of LGM ELAs in the northeast part of the range is supported by recent field mapping, where anomalous ice distribution and ELAs reflect complicated LGM climate patterns and possibly late Quaternary tectonism. Copyright © 2005 John Wiley & Sons, Ltd.
Moraine preservation and boulder erosion in the tropical Andes: interpreting old surface exposure ages in glaciated valleys
Authors: Smith Jacqueline A. , Finkel Robert C. , Farber Daniel L. , Rodbell Donald T. , Seltzer Geoffrey O.
Published: December 2005

Cosmogenic dating provides a long‐awaited means of directly dating glacial deposits that pre‐date the last glacial cycle. Although the potential benefits of longer chronologies are obvious, the greater uncertainty associated with older cosmogenic ages may be less readily apparent. We illustrate the challenges of developing and interpreting a long chronology using our data from the Peruvian Andes. We used surface exposure dating with cosmogenic radionuclides (CRNs; 10Be and 26Al) to date 140 boulders on moraines in valleys bordering the Junin Plain (11° S, 76° W) in central Peru. Our chronology spans multiple glacial cycles and includes exposure ages greater than 1 million years, which indicate that long‐term rates of boulder erosion have been very low. Interpreting the chronology of moraines for glaciations that predate the last glacial cycle is complicated by the need to consider boulder erosion and exhumation, surface uplift, and inheritance of CRNs from previous exposure intervals. As an example, we recalculate exposure ages using our boulder erosion rates (0.3–0.5 metres per million years) and estimated surface uplift rates to emphasise both the challenges involved in interpreting old surface exposure ages and the value of chronological data, even with large uncertainties, when reconstructing the palaeoclimate of a region. Copyright © 2005 John Wiley & Sons, Ltd.
Comparing reconstructed Pleistocene equilibrium‐line altitudes in the tropical Andes of central Peru
Authors: Ramage Joan M. , Smith Jacqueline A. , Rodbell Donald T. , Seltzer Geoffrey O.
Published: December 2005

Glacier equilibrium‐line altitude (ELA), and the difference between modern and palaeo‐ELA can be interpreted as a proxy for climate change. One issue in ELA reconstruction is that different methods of ΔELA reconstruction may produce a range of results for the same palaeoglacier. When a range of methods is used to reconstruct ELAs across a region, resulting variations may be related to the method rather than the past climate. Palaeoclimatic interpretation of ELAs that were reconstructed by different methods may prompt spurious inferences if the ELA range is the result of methodological differences rather than climatic variation. We address the relationship and degree of variation between methods by comparing terminus‐to‐headwall‐altitude ratio (THAR), accumulation–area ratio (AAR), and accumulation‐area balance ratio (AABR) methods for palaeoglaciers in four valleys in the tropical Andes. Valleys in the eastern cordillera of the Peruvian Andes bordering the Junin Plain (11° S, 76° W, ca. 4100 m a.s.l.) are presently ice‐free but were glaciated repeatedly during the Pleistocene. We use a combination of 90‐m shuttle radar topography mission (SRTM) data, 15‐m Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data, and 1:25 000 topographic maps to reconstruct ELAs. Within each of three groups of moraines, map‐based THAR and AABR estimates of ELA tend to be highest, followed by DEM‐derived THAR ELAs, with AAR‐reconstructed ELAs somewhat lower in this region. ELA estimates for the local Last Glacial Maximum (LLGM) range from ca. 4250 to 4570 m a.s.l., with ΔELAs of ca. −220 to −550 m (depending on valley and method used). Within individual valleys, ΔELAs for the same palaeoglaciers calculated by different methods vary by ± 100 m. ELAs of the LLGM glaciers and those of the largest glaciers to occupy the Junin valleys (> 65 ka) are not markedly different from each other, regardless of the method used in their calculation, which is largely a reflection of the valley hypsometry in the region. Our analysis suggests relatively low decreases in temperature during glacial periods in the region (ca. 2.5± 1°C). Copyright © 2005 John Wiley & Sons, Ltd.
Contrasts in the Quaternary of mid‐North America and mid‐Eurasia: notes on Quaternary landscapes of western Siberia
Authors: Wright H. E.
Published: December 2005

The West Siberian Plain was formed by marine deposits that extended from the Mediterranean basin to the arctic. Tectonic action later produced a striking series of long straight NE–SW grabens in the southern part of the plain. Pleistocene advance of the Kara ice sheet onto the continent resulted in blockage of the Ob and Yenisey rivers to form huge proglacial lakes that drained through these grabens south via the Turgay Pass and the Aral, Caspian, Black and Mediterranean seas to the North Atlantic Ocean, but during the Last Glacial Maximum (late Weichselian, isotope stage 2), the Kara ice sheet did not advance onto the continent in northwestern Siberia. The Altai Mountains, which bound the West Siberian Plain on the south, contained large deep intermontane ice‐dammed lakes, which drained catastrophically when the ice dams broke, forming giant ripples on the basin floors. Pollen studies of glacial lakes indicate that the Lateglacial steppe vegetation and dry climatic conditions continued into the early Holocene as summer insolation maintained high levels. Permafrost development on a drained lake floor in the western Altai Mountains resulted in the formation of groups of small pingos. In North America the growth and wastage of the huge Laurentide ice sheet had an indirect role in the climatic history of western Siberia during the Glacial and Lateglacial periods, after which the climate was more affected directly by insolation changes, whereas in North America in the early Holocene the insolation factor was coupled with the climatic effects of the slow wastage of the ice sheet, and the time of maximum dryness was postponed until the mid‐Holocene. Copyright © 2005 John Wiley & Sons, Ltd.
Late Quaternary palaeolakes, rivers, and wetlands on the Bolivian Altiplano and their palaeoclimatic implications
Authors: Rigsby Catherine A. , Bradbury J. Platt , Baker Paul A. , Rollins Stephanie M. , Warren Michelle R.
Published: December 2005

Drill cores of sediments from the Rio Desaguadero valley, Bolivia, provide new information about the climate of tropical South America over the past 50 000 years. The modern Rio Desaguadero is fed by Lake Titicaca overflow (and by local tributaries) in the wetter northern Altiplano and discharges into Lake Poopo in the more arid central Altiplano. During the late Quaternary the Rio Desaguadero valley was the site of several generations of palaeolakes and wetlands that formed during periods of increased precipitation and local runoff, augmented by increased overflow from Lake Titicaca. Sediments recovered by drilling in eight localities along the 390‐km long valley of the Rio Desaguadero yield a regional history of lacustrine sedimentation and effective precipitation. Lacustrine strata in the drill cores record 12 distinct wet periods in the past 50 000 years. Four of these wet periods resulted in the formation of major palaeolakes in the Rio Desaguadero valley: during the last glacial maximum from before 20 000 to 16 000 cal. yr BP, during the late glacial from about 14 000 to 12 000 cal. yr BP, in the early Holocene from about 10 000 to 7900 cal. yr BP, and in the late Holocene from 4500 cal. yr BP to present. The period that appears to have been most arid was between 7900 and 4500 cal. yr BP. The Altiplano wet periods were generally synchronous with North Atlantic cold events (respectively, the last glacial maximum, the Younger Dryas, the 8200 cal. yr BP event, and the Neoglacial) implying a relationship between past precipitation variability in tropical South America and North Atlantic sea‐surface temperature. Copyright © 2005 John Wiley & Sons, Ltd.
The age and extent of tropical alpine glaciation in the Cordillera Blanca, Peru
Authors: Farber Daniel L. , Hancock Gregory S. , Finkel Robert C. , Rodbell Donald T.
Published: December 2005

Based on new 10Be data for moraines in the Cordillera Blanca of central Peru, we have calculated model ages of three sets of Pleistocene glacial moraines. In order of decreasing age, these are the Cojup, Rurec and Laguna Baja moraines. The oldest moraines occur at the lowest elevations and yield dates of >400 ka pre‐dating the last interglacial and demonstrating that maximum ice volumes occurred during previous glacial periods, and not at the end of the last glacial. Our new data from the younger moraines indicate that the end of the last glacial cycle comprised two separate advances at ca. 29 ka and ca. 16.5 ka, each reflecting significant (>4°C) tropical of cooling at 10° S. These data combined with published records from the Laurentide ice sheet, indicate that climate instabilities associated with the close of the last glacial were likely global and synchronous in nature. Copyright © 2005 John Wiley & Sons, Ltd.
Mango ripening: changes in cell wall constituents in relation to textural softening
Authors: Yashoda Hosakote M , Prabha Tyakal N , Tharanathan Rudrapatnam N
Published: December 2005

Ripening of mango (Mangifera indica L., cv. Alphonso) fruit is characterized by a series of biochemical changes resulting in gradual textural softening. From unripe to ripe stage, the starch content came down from 18% to 0.1%; pectin from 1.9% to 0.5%; cellulose from 2% to 0.9% and hemicelluloses from 0.8% to 0.2%. Concomitantly, the total soluble solids increased from 7% to 20%, total soluble sugars from 1% to 15% and pH increased from 2.8 to 5.1. The increase in activity of several of the carbohydrate‐degrading enzymes, which resulted in solubilization of the various polysaccharide fractions, correlated with fruit‐softening phenomenon. Efficient distribution of 14C‐starch into glucose, fructose and sucrose revealed considerable sugar interconversions indicating active gluconeogenesis during mango fruit ripening. Copyright © 2005 Society of Chemical Industry
Gene expression profiling reveals intrinsic differences between T‐cell acute lymphoblastic leukemia and T‐cell lymphoblastic lymphoma
Authors: Raetz Elizabeth A. , Perkins Sherrie L. , Bhojwani Deepa , Smock Kristi , Philip Mary , Carroll William L. , Min Dong‐Joon
Published: December 2005

Background

T‐cell acute lymphoblastic leukemia (T‐ALL) and T‐cell lymphoblastic lymphoma (T‐LL) and are often thought to represent a spectrum of a single disease. The malignant cells in T‐ALL and T‐LL are morphologically indistinguishable, and they share the expression of common cell surface antigens and cytogenetic characteristics. However, despite these similarities, differences in the clinical behavior of T‐ALL and T‐LL are observed.

Procedure

We analyzed the gene expression profiles of T‐ALL and T‐LL samples obtained from Children's Oncology Group (COG) tumor banks using DNA arrays. Immunohistochemistry was also performed to validate the expression of selected targets.

Results

Unsupervised hierarchical clustering of all samples showed complete segregation of T‐ALL and T‐LL into distinct clusters. Next, we identified the top 201 genes that best differentiated T‐ALL from T‐LL using significance analysis of microarrays (SAM), a supervised statistical approach. Genes representing several functional groups were differentially expressed in T‐LL and T‐ALL. Prediction analysis of microarrays (PAM) identified a subset of genes, which accurately classified all 19 T‐ALL and T‐LL samples with an overall misclassification error rate of 0. Immunohistochemical validation of protein expression of selected genes identified by microarray analysis confirmed overexpression of MLL‐1 in T‐LL tumor cells compared to T‐ALL and CD47 in T‐ALL tumors cells when compared to T‐LL.

Conclusions

Despite significant similarities between the malignant T‐cell precursors, clear differences in the gene expression profiles were observed between T‐ALL and T‐LL implying underlying differences in the biology of the two entities. Pediatr Blood Cancer © 2005 Wiley‐Liss, Inc.
High serum values of soluble CD154, IL‐2 receptor, RANKL and osteoprotegerin in Langerhans cell histiocytosis
Authors: Ishii Rumiko , Morimoto Akira , Ikushima Satoshi , Sugimoto Tohru , Asami Keiko , Bessho Fumio , Kudo Kazuko , Tsunematu Yukiko , Fujimoto Junichiro , Imashuku Shinsaku
Published: December 2005

Background

To determine useful biochemical markers in Langerhans cell histiocytosis (LCH), we analyzed the serum levels of soluble CD154 (sCD154), IL2 receptor (sIL2‐R), receptor activator of NF‐κB ligand (sRANKL), and osteoprotegerin (OPG).

Procedure

Our study included 46 newly diagnosed LCH patients (single‐system multi‐site (SM type): n = 20, and multi‐system multi‐site (MM type): n = 26) who were treated with the JLSG‐02 protocol between 2002 and 2004. The median age of the patients was 3.8 years old (range 0–18). sCD154, sIL2‐R, sRANKL, and OPG were measured by ELISA at diagnosis (n = 46) and after 6‐weeks of induction therapy (n = 14).

Results

The values of sCD154, sIL‐2R, sRANKL, and OPG, and the sRANKL/OPG ratio in sera were significantly higher in patients with LCH compared with controls (1.83 ± 1.38 vs. 0.22 ± 0.16 ng/ml, P < 0.001; 1,600 ± 1,060 vs. 420 ± 160 pg/ml, P < 0.001; 1.72 ± 1.20 vs. 1.04 ± 1.09 pmol/L, P = 0.019; 6.34 ± 2.94 vs. 3.71 ± 2.03 pmol/L, P < 0.001; and 0.40 ± 0.45 vs. 0.16 ± 0.17, P = 0.023, respectively). Serum levels of sIL‐2R were significantly elevated in the MM type compared with the SM type (2,050 ± 1,060 vs. 870 ± 340 pg/ml, P < 0.001). Serum OPG levels were also significantly elevated in the MM type compared with the SM type (7.58 ± 2.72 vs. 5.13 ± 2.69 pmol/L, P = 0.008) and negatively correlated with the number of bone lesions (r = −0.56, P = 0.007). In contrast, the sRANKL/OPG ratios were significantly higher in the SM type than the MM type (0.57 ± 0.54 vs. 0.19 ± 0.14, P = 0.002) and positively correlated with the number of bone lesions (r = 0.34, P = 0.040). In patients who responded to the induction therapy, serum levels of sIL‐2R, sRANKL, and OPG, and the sRANKL/OPG ratio decreased significantly after the therapy (1,170 ± 600 vs. 730 ± 290 pg/ml, P = 0.029; 2.19 ± 1.06 vs. 1.24 ± 0.66 pmol/L, P < 0.001; 6.13 ± 2.40 vs. 4.72 ± 2.03 pmol/L, P = 0.040; and 0.57 ± 0.52 vs. 0.41 ± 0.37, P = 0.02, respectively). In the three patients who did not respond to the induction therapy, the serum levels of sCD154 increased significantly after the therapy (1.3 ± 1.1 vs. 2.7 ± 1.2, P = 0.004).

Conclusions

Serum levels of sIL‐2R and sCD154 could be useful as indicators of inflammation and sRANKL/OPG ratios as markers of osteolytic activity in LCH patients. Pediatr Blood Cancer © 2005 Wiley‐Liss, Inc.