bluuebunny/crossref_metadata_2025_split huggingface dataset:
Millennial-scale climate changes on South Georgia, Southern Ocean
Authors: Rosqvist Gunhild C. , Schuber Pernilla 
Published: May 2003

AbstractThe location of South Georgia (54°S, 36°W) makes it a suitable site for the study of the climatic connections between temperate and polar environments in the Southern Hemisphere. Because the mass balance of the small cirque glaciers on South Georgia primarily responds to changes in summer temperature they can provide records of changes in the South Atlantic Ocean and atmospheric circulation. We use grey scale density, weight-loss-on-ignition, and grain size analyses to show that the proportion of glacially eroded sediments to organic sediments in Block Lake was highly variable during the last 7400 cal yr B.P. We expect that the glacial signal is clearly detectable above noise originating from nonglacial processes and assume that an increase in glacigenic sediment deposition in Block Lake has followed Holocene glacier advances. We interpret proglacial lake sediment sequences in terms of summer climate warming and cooling events. Prominent millennial-scale features include cooling events between 7200 and 7000, 5200 and 4400, and 2400 and 1600 cal yr B.P. and after 1000 cal yr B.P. Comparison with other terrestrial and marine records reveals that the South Georgian record captures all the important changes in Southern Hemisphere Holocene climate. Our results reveal a tentative coupling between climate changes in the South Atlantic and North Atlantic because the documented temperature changes on South Georgia are anti-phased to those in the North Atlantic.
Unprecedented last-glacial mass accumulation rates determined by luminescence dating of loess from western Nebraska
Authors: Roberts Helen M. , Muhs Daniel R. , Wintle Ann G. , Duller Geoff A. T. , Bettis E. Arthur 
Published: May 2003

AbstractA high-resolution chronology for Peoria (last glacial period) Loess from three sites in Nebraska, midcontinental North America, is determined by applying optically stimulated luminescence (OSL) dating to 35–50 μm quartz. At Bignell Hill, Nebraska, an OSL age of 25,000 yr near the contact of Peoria Loess with the underlying Gilman Canyon Formation shows that dust accumulation occurred early during the last glacial maximum (LGM), whereas at Devil’s Den and Eustis, Nebraska, basal OSL ages are significantly younger (18,000 and 21,000 yr, respectively). At all three localities, dust accumulation ended at some time after 14,000 yr ago. Mass accumulation rates (MARs) for western Nebraska, calculated using the OSL ages, are extremely high from 18,000 to 14,000 yr—much higher than those calculated for any other pre-Holocene location worldwide. These unprecedented MARs coincide with the timing of a mismatch between paleoenvironmental evidence from central North America, and the paleoclimate simulations from atmospheric global circulation models (AGCMs). We infer that the high atmospheric dust loading implied by these MARs may have played an important role, through radiative forcing, in maintaining a colder-than-present climate over central North America for several thousand years after summer insolation exceeded present-day values.
Coral δ18O records as an indicator of winter monsoon intensity in the South China Sea
Authors: Peng Zicheng , Chen Tegu , Nie Baofu , Head M. John , He Xuexian , Zhou Weijian 
Published: May 2003

AbstractWe have used correlative analysis between mean December–January–February winter wind velocities, measured at the Xisha Meteorological Observatory (16°50′N, 112°20′E) in the middle of the South China Sea, and mean δ18O data for the corresponding month from Porites lutea coral, collected in Longwan waters (19°20′N, 110°39′E), to obtain a linear equation relating the two datasets. This winter wind velocity for the South China Sea (WMIIscs) can then be correlated to the coral δ18O by the equation WMIIscs = −1.213–1.351 δ18O (‰ PDB), r = −0.60, n = 40, P = 0.01. From this, the calculated WMIIscs-δ18O series from 1944 to 1997 tends to decrease during the 1940s to the 1960s; it increases slightly during the 1970s and then decreases again in the 1980s and 1990s. The calculated decadal mean WMIIscs-δ18O series had a obvious decrease from 5.92 to 4.63 m/s during the period of 1944–1997. The calculated yearly mean WMIIscs-δ18O value is 5.58 m/s from 1944 to 1976 and this decreases to 4.85 m/s from 1977 to 1998. That is the opposite trend to the observed yearly mean SST variation. The yearly mean SST anomaly is −0.27° from 1943 to 1976 and this increases to +0.16° from 1977 to 1998. Spectral analysis used on a 54-year-long calculated WMIIscs-δ18O series produces spectral peaks at 2.4–7 yr, which can be closely correlated with the quasibiennial oscillation band (QBO band, 2–2.4 yr) and the El Ñino southern oscillation band (ENSO band, 3–8 yr). Hence most of the variability of the winter monsoon intensity in the middle of the South China Sea is mainly constrained by changes in the thermal difference between the land and the adjoining sea area, perhaps due to global warming.
Predicting Gene Ontology Biological Process From Temporal Gene Expression Patterns
Authors: Lægreid Astrid , Hvidsten Torgeir R. , Midelfart Herman , Komorowski Jan , Sandvik Arne K. 
Published: May 2003

The aim of the present study was to generate hypotheses on the involvement of uncharacterized genes in biological processes. To this end, supervised learning was used to analyze microarray-derived time-series gene expression data. Our method was objectively evaluated on known genes using cross-validation and provided high-precision Gene Ontology biological process classifications for 211 of the 213 uncharacterized genes in the data set used. In addition, new roles in biological process were hypothesized for known genes. Our method uses biological knowledge expressed by Gene Ontology and generates a rule model associating this knowledge with minimal characteristic features of temporal gene expression profiles. This model allows learning and classification of multiple biological process roles for each gene and can predict participation of genes in a biological process even though the genes of this class exhibit a wide variety of gene expression profiles including inverse coregulation. A considerable number of the hypothesized new roles for known genes were confirmed by literature search. In addition, many biological process roles hypothesized for uncharacterized genes were found to agree with assumptions based on homology information. To our knowledge, a gene classifier of similar scope and functionality has not been reported earlier.[Supplemental material is available online atwww.genome.org. All annotations, reclassifications of known genes, and classifications of uncharacterized genes are available online athttp://www.lcb.uu.se/∼hvidsten/fibroblast.]
Complex Evolution of 7E Olfactory Receptor Genes in Segmental Duplications
Authors: Newman Tera , Trask Barbara J. 
Published: May 2003

Large segmental duplications (SDs) constitute at least 3.6% of the human genome and have increased its size, complexity, and diversity. SDs can mediate ectopic sequence exchange resulting in gross chromosomal rearrangements that could contribute to speciation and disease. We have identified and evaluated a subset of human SDs that harbor an 88-member subfamily of olfactory receptor (OR)-like genes called the 7Es. At least 92% of these genes appear to be pseudogenes when compared to other OR genes. The 7E-containing SDs (7E SDs) have duplicated to at least 35 regions of the genome via intra- and interchromosomal duplication events. In contrast to many human SDs, the 7E SDs are not biased towards pericentromeric or subtelomeric regions. We find evidence for gene conversion among 7E genes and larger sequence exchange between 7E SDs, supporting the hypothesis that long, highly similar stretches of DNA facilitate ectopic interactions. The complex structure and history of the 7E SDs necessitates extension of the current model of large-scale DNA duplication. Despite their appearance as pseudogenes, some 7E genes exhibit a signature of purifying selection, and at least one 7E gene is expressed.[Supplemental material is available online atwww.genome.org.]
Genome Size Evolution in Pufferfish: A Comparative Analysis of Diodontid and Tetraodontid Pufferfish Genomes
Authors: Neafsey Daniel E. , Palumbi Stephen R. 
Published: May 2003

Smooth pufferfish of the family Tetraodontidae have the smallest vertebrate genomes yet measured. They have a haploid genome size of ∼400 million bp (Mb), which is almost eight times smaller than the human genome. Given that spiny pufferfish from the sister family Diodontidae and a fish from the outgroup Molidae have genomes twice as large as smooth puffers, it appears that the genome size of smooth puffers has contracted in the last 50–70 million years since their divergence from the spiny puffers. Here we use renaturation kinetics to compare the repetitive nature of the smooth and spiny puffer genomes. We also estimate the rates of small (<400 bp) insertions and deletions in smooth and spiny puffers using defunct non-LTR retrotransposons. We find a significantly greater abundance of a transposon-like repetitive DNA class in spiny puffers relative to smooth puffers, in addition to nearly identical indel rates. We comment on the role that large insertions may play in the evolution of genome size in these two groups.[The sequence data from this study have been submitted to GenBank under accession nos. AY212336–AY212504.]
In Situ-Synthesized Novel Microarray Optimized for Mouse Stem Cell and Early Developmental Expression Profiling
Authors: Carter Mark G. , Hamatani Toshio , Sharov Alexei A. , Carmack Condie E. , Qian Yong , Aiba Kazuhiro , Ko Naomi T. , Dudekula Dawood B. , Brzoska Pius M. , Hwang S. Stuart , Ko Minoru S.H. 
Published: May 2003

Applications of microarray technologies to mouse embryology/genetics have been limited, due to the nonavailability of microarrays containing large numbers of embryonic genes and the gap between microgram quantities of RNA required by typical microarray methods and the miniscule amounts of tissue available to researchers. To overcome these problems, we have developed a microarray platform containing in situ-synthesized 60-mer oligonucleotide probes representing approximately 22,000 unique mouse transcripts, assembled primarily from sequences of stem cell and embryo cDNA libraries. We have optimized RNA labeling protocols and experimental designs to use as little as 2 ng total RNA reliably and reproducibly. At least 98% of the probes contained in the microarray correspond to clones in our publicly available collections, making cDNAs readily available for further experimentation on genes of interest. These characteristics, combined with the ability to profile very small samples, make this system a resource for stem cell and embryogenomics research.[Supplemental material is available online atwww.genome.organd at the NIA Mouse cDNA Project Web site,http://lgsun.grc.nia.nih.gov/cDNA/cDNA.html.]
Genome-Wide In Silico Identification of Transcriptional Regulators Controlling the Cell Cycle in Human Cells
Authors: Elkon Ran , Linhart Chaim , Sharan Roded , Shamir Ron , Shiloh Yosef 
Published: May 2003

Dissection of regulatory networks that control gene transcription is one of the greatest challenges of functional genomics. Using human genomic sequences, models for binding sites of known transcription factors, and gene expression data, we demonstrate that the reverse engineering approach, which infers regulatory mechanisms from gene expression patterns, can reveal transcriptional networks in human cells. To date, such methodologies were successfully demonstrated only in prokaryotes and low eukaryotes. We developed computational methods for identifying putative binding sites of transcription factors and for evaluating the statistical significance of their prevalence in a given set of promoters. Focusing on transcriptional mechanisms that control cell cycle progression, our computational analyses revealed eight transcription factors whose binding sites are significantly overrepresented in promoters of genes whose expression is cell-cycle-dependent. The enrichment of some of these factors is specific to certain phases of the cell cycle. In addition, several pairs of these transcription factors show a significant co-occurrence rate in cell-cycle-regulated promoters. Each such pair indicates functional cooperation between its members in regulating the transcriptional program associated with cell cycle progression. The methods presented here are general and can be applied to the analysis of transcriptional networks controlling any biological process.[Supplemental material is available online atwww.genome.org, including full lists of genes whose promoters were found to contain high scoring sites for any of the enriched transcription factors reported in Tables 1 and 3.]
Analysis of the ArabidopsisMADS AFFECTING FLOWERINGGene Family:MAF2Prevents Vernalization by Short Periods of Cold [W]
Authors: Ratcliffe Oliver J. , Kumimoto Roderick W. , Wong Becky J. , Riechmann José Luis 
Published: May 2003

AbstractThe Arabidopsis FLOWERING LOCUS C (FLC) gene is a key floral repressor in the maintenance of a vernalization response. In vernalization-sensitive genetic backgrounds, FLC levels are high, and they decline after exposure to long cold periods. Four FLC paralogs (MAF2 [MADS AFFECTING FLOWERING2] to MAF5) are arranged in a tandem array on the bottom of Arabidopsis chromosome V. We used a reverse genetics approach to analyze their functions. Loss-of-function and gain-of-function studies indicate that MAF2 acts as a floral repressor. In particular, maf2 mutant plants display a pronounced vernalization response when subjected to relatively short cold periods, which are insufficient to elicit a strong flowering response in the wild type, despite producing a large reduction in FLC levels. MAF2 expression is less sensitive to vernalization than that of FLC, and its repressor activity is exerted independently or downstream of FLC transcription. Thus, MAF2 can prevent premature vernalization in response to brief cold spells. Overexpression of MAF3 or MAF4 produces alterations in flowering time that suggest that these genes also act as floral repressors and might contribute to the maintenance of a vernalization requirement. However, the final gene in the cluster, MAF5, is upregulated by vernalization. Therefore, MAF5 could play an opposite role to FLC in the vernalization response.
The ArabidopsisSLEEPY1Gene Encodes a Putative F-Box Subunit of an SCF E3 Ubiquitin Ligase[W]
Authors: McGinnis Karen M. , Thomas Stephen G. , Soule Jonathan D. , Strader Lucia C. , Zale Janice M. , Sun Tai-ping , Steber Camille M. 
Published: May 2003

AbstractThe Arabidopsis SLY1 (SLEEPY1) gene positively regulates gibberellin (GA) signaling. Positional cloning of SLY1 revealed that it encodes a putative F-box protein. This result suggests that SLY1 is the F-box subunit of an SCF E3 ubiquitin ligase that regulates GA responses. The DELLA domain protein RGA (repressor of ga1-3) is a repressor of GA response that appears to undergo GA-stimulated protein degradation. RGA is a potential substrate of SLY1, because sly1 mutations cause a significant increase in RGA protein accumulation even after GA treatment. This result suggests SCFSLY1-targeted degradation of RGA through the 26S proteasome pathway. Further support for this model is provided by the observation that an rga null allele partially suppresses the sly1-10 mutant phenotype. The predicted SLY1 amino acid sequence is highly conserved among plants, indicating a key role in GA response.
Rapid Genome Divergence at Orthologous Low Molecular Weight Glutenin Loci of the A and Am Genomes of Wheat[W]
Authors: Wicker Thomas , Yahiaoui Nabila , Guyot Romain , Schlagenhauf Edith , Liu Zhong-Da , Dubcovsky Jorge , Keller Beat 
Published: May 2003

AbstractTo study genome evolution in wheat, we have sequenced and compared two large physical contigs of 285 and 142 kb covering orthologous low molecular weight (LMW) glutenin loci on chromosome 1AS of a diploid wheat species (Triticum monococcum subsp monococcum) and a tetraploid wheat species (Triticum turgidum subsp durum). Sequence conservation between the two species was restricted to small regions containing the orthologous LMW glutenin genes, whereas &gt;90% of the compared sequences were not conserved. Dramatic sequence rearrangements occurred in the regions rich in repetitive elements. Dating of long terminal repeat retrotransposon insertions revealed different insertion events occurring during the last 5.5 million years in both species. These insertions are partially responsible for the lack of homology between the intergenic regions. In addition, the gene space was conserved only partially, because different predicted genes were identified on both contigs. Duplications and deletions of large fragments that might be attributable to illegitimate recombination also have contributed to the differentiation of this region in both species. The striking differences in the intergenic landscape between the A and Am genomes that diverged 1 to 3 million years ago provide evidence for a dynamic and rapid genome evolution in wheat species.
POLYBIUS AND THE EVIDENCE FOR PERIPHRASTIC ΟΙ ΠΕΡΙ ΤΙΝΑ
Authors: Gorman Robert 
Published: May 2003

AbstractThe current view about the construction oι περι + acc. nominis proprii is subject to doubt. The most thorough investigation of the phrase maintains that in narrative prose of the Hellenistic and Roman period the periphrastic use (i.e., oι περι τινα as the equivalent of the proper name alone) is common when περι governs two or more names, but unevidenced if the preposition has only one object. The pattern is said to have been already fully formed when it first appeared in the Histories of Polybius. The evidence from that author, however, does not support this view. Each of the passages offered as clear examples of periphrasis admits of a more plausible interpretation. For some, the context makes clear that Polybius has in mind specific referents for the phrase which cannot then be periphrastic. In other passages the phrase belongs to one of several types recognizable according to Polybian usage, whose details tell against the periphrastic interpretation. Thus, oι περι X and oι περι X και Y are indistinct with respect to this usage and there is no certain instance of periphrastic o περ τινα in the Histories, the work with which this idiom is perhaps most closely identified.
"THE USE OF SUNDAY FOR MEETINGS OF BELIEVERS IN THE NEW TESTAMENT": A RESPONSE
Authors: Young Norman 
Published: May 2003

AbstractS. R. Llewelyn's recent study on Sunday in the NT attempts to prove that first-century Christians were regularly meeting together on the first day of the week. His available evidence is sparse, and his conclusions lack cogent support. His effort to demonstrate that the offering in 1 Cor. 16:2 was in a Christian assembly falls short of proof. Likewise his argument that Acts 20:7 proves that Christians assembled to celebrate the Eucharist on Sunday is not coercive. Finally the inference that Rev. 1:10 points to Sunday as a time of regular Christian assembly is more than the language of the text warrants.
Subpopulations at increased risk of adverse health outcomes from air pollution
Authors: Annesi-Maesano I. , Agabiti N. , Pistelli R. , Couilliot M‐F. , Forastiere F. 
Published: May 2003

Epidemiological research to identify subpopulations with enhanced susceptibility to air pollution is still at an early stage.From the available studies, there is evidence that both “endogenous” and “exogenous” factors contribute to individual susceptibility. Females and the elderly are at an increased risk of pollution-related diseases. Moreover, some chronic clinical conditions seem to be good candidates for identifying the “frail” populations: chronic obstructive pulmonary disease including asthma, coronary heart diseases, congestive heart failure, and heart rhythm disorders.It seems clear that epidemiological research on susceptibility in the future should investigate the underlying biological and physiological mechanisms, in addition to the environmental and toxicological effects.
Particulate air pollution and hospital admissions for cardiorespiratory diseases: are the elderly at greater risk?
Authors: Anderson H.R. , Atkinson R.W. , Bremner S.A. , Marston L. 
Published: May 2003

A systematic literature review suggests that particulate air pollution is associated with daily admissions for both respiratory and cardiac diseases in people aged >65 yrs.A model of acute effects is proposed which shows how admissions can be brought forward by a relatively short period of time as well as events being added that would not have happened at all except for air pollution. A model of the effects of air pollution on chronic disease is proposed that provides the background of long-term vulnerability upon which the increased short-term vulnerability is superimposed.A study of daily hospital admissions in London shows that for respiratory disease the relative risks of admission associated with particles reduce with increasing age, while for cardiac disease, there is no trend. When the attributable risk is estimated using baseline admission rates for respiratory disease, it is children who have the highest attributable risk, followed by the elderly.For cardiac disease there is a steep increase in attributable risk with age, reflecting the dominant influence of baseline risks. The attributable risk for cardiovascular disease in the elderly is considerably greater than for respiratory disease, due to higher baseline admission rates.
Questionnaires, spirometry and PEF monitoring in epidemiological studies on elderly respiratory patients
Authors: Bellia V. , Pistelli F. , Giannini D. , Scichilone N. , Catalano F. , Spatafora M. , Hopps R. , Carrozzi L. , Baldacci S. , Di Pede F. , Paggiaro P. , Viegi G. 
Published: May 2003

Questionnaires are the most used subjective instrument of measurement in respiratory epidemiology. The standardisation of the questionnaires aims to limit bias by maximising validity and reliability, and comparability. Within the European Union project BIOMED1, a compendium of respiratory standard questionnaires (CORSQ) was developed for adults covering 18 topics from general information to early life events, through environmental risk factors and respiratory symptoms and diseases.Reliable spirometry data needs a rigorous quality control programme, as in the “Salute Respiratoria nell'Anziano” (Sa.R.A.) project, Italian for “Respiratory Health in the Elderly”. Reproducibility rates were 95.8% for forced expiratory volume in one second (FEV1). Male sex and age were independent risk factors for a poorer reproducibility, as well as cognitive and physical impairment (shorter 6‐min walking distance) and lower educational level for a poorer acceptability. Reference values for people aged 65–85 yrs have been produced; these results suggest that the effect of aging should be corrected for physical and mental disability. A revision of interpretative strategies included in current guidelines is needed.Peak expiratory flow monitoring has several methodological problems: reliability and sensitivity of the measurement in order to detect changes in airway calibre; compliance with long-term monitoring; choice of the best variability index; difference between asthmatic and nonasthmatic subjects; age-related differences. Despite these methodological problems, peak expiratory flow monitoring has been successfully used in the evaluation of the effects of air pollution in normal and asthmatic subjects, and in the elderly.