bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of p16INK4A mediated by β‐catenin in a TCF4‐independent manner: Implications for alterations in p16INK4A and pRb expression during trans‐differentiation of endometrial carcinoma cells
Authors: Saegusa Makoto , Hashimura Miki , Kuwata Takeshi , Hamano Mieko , Okayasu Isao 
Published: July 2006

AbstractExcessive β‐catenin is considered to contribute to tumor progression by inducing transcription of cell cycle‐related genes such as cyclin D1 and c‐myc. In contrast, our recent studies demonstrated that β‐catenin could inhibit cell proliferation through activation of p14ARF/p53/p21WAF1 pathway during trans‐differentiation toward morular phenotype of endometrial carcinoma (Em Ca) cells. Here, we focused on associations with alterations in p16INK4A and pRb expression during this process. In clinical cases, p16INK4A immunoreactivity was found to frequently overlap with nuclear β‐catenin accumulation in small‐sized morules and surrounding glandular carcinomas (Sur‐Ca), demonstrating a significant positive correlation (r = 0.447, p < 0.0001) overall, while the immunoreactions showed stepwise decrease in enlarged morules, despite persistent accumulation of β‐catenin and p21WAF1 in nuclei. Immunoreactivity for both total pRb and its phosphorylated form was apparently decreased in all morules as compared to Sur‐Ca lesions, with a significantly positive correlation. In cell lines, transcriptional activation of p16INK4A promoter by active form β‐catenin, as well as p21WAF1, occurred through the region from −385 to −280 bp relative to the translation start site, in a TCF4‐independent manner. Moreover, cell proliferation was accompanied with phosphorylation of pRb and increased p16INK4A expression, while its inhibition by serum starvation caused decreased expression of total pRb but not p16INK4A, resulting in high relative amounts of the latter. These findings indicate that induction of p16INK4A mediated by nuclear β‐catenin and p21WAF1, along with loss of pRb expression, may be important for initial steps during trans‐differentiation of Em Ca cells. In addition, its down‐regulation is associated with progression of lesions. © 2006 Wiley‐Liss, Inc.
Nonattendance is still the main limitation for the effectiveness of screening for cervical cancer in the Netherlands
Authors: Bos Anita B. , Rebolj Matejka , Habbema J. Dik F. , van Ballegooijen Marjolein 
Published: July 2006

AbstractAlthough mass screening for cervical cancer has been operational for more than 2 decades in the Netherlands, 700 women are still diagnosed with this cancer each year (9 per 100,000). We investigated these cases, in order to evaluate opportunities to further increase the effectiveness of the programme. We analyzed the screening history of women diagnosed with cervical cancer between 1994–1997 using the Dutch national pathology file that includes cervical cytology and histological results. More than half of the cases did not have previous preventive cervical smears, and another 30% had never been invited to the programme because of their age. In the future, we estimate that two thirds of all Dutch women with invasive cervical cancer will be unscreened or under‐screened, based on current screening participation of more than 70%. We conclude that increasing screening participation has much more potential for further reducing cervical cancer incidence than reducing the screening interval, increasing the age range or having a screening test with higher sensitivity. © 2006 Wiley‐Liss, Inc.
Gleason score, age and screening: Modeling dedifferentiation in prostate cancer
Authors: Draisma Gerrit , Postma Renske , Schröder Fritz H. , van der Kwast Theo H. , de Koning Harry J. 
Published: July 2006

AbstractTumor differentiation as measured by the Gleason score is highly predictive of the course of prostatic cancer after diagnosis. Since the introduction of the prostate‐specific antigen (PSA) test tumors are diagnosed with a favorable tumor stage and differentiation grade. Does screening with PSA just detect more tumors with favorable characteristics or is dedifferentiation actually being prevented by early detection and consequent treatment? The latter option implies that tumors dedifferentiate in the preclinical screen‐detectable phase. To model the natural history of prostate cancer, we analyzed the age‐specific distribution of clinical stage and Gleason score of 2,204 tumors diagnosed in the ERSPC‐Rotterdam trial. We fitted 2 MISCAN simulation models to the observed data: Model I where tumors dedifferentiate before becoming screen‐detectable and Model II where dedifferentiation occurs during the screen‐detectable preclinical phase. The hypothesis of dedifferentiation during the screen‐detectable phase was tested by a goodness of fit test of both models. In ERSPC‐Rotterdam, we observed a significantly more favorable distribution of Gleason scores in screen‐detected cancers compared to cancers found in the control arm, and in cancers detected in the second round compared to cancers detected in the first round of screening. Also, a significant association between Gleason score and age at diagnosis was found, most notably in cancers detected in the first round of screening. These findings were reproduced by Model II and less so by Model I, with a significant difference in goodness of fit between the 2 models (p< 0.001). This study provides epidemiological evidence of dedifferentiation as a major mechanism of progression in prostate cancer. Tumors dedifferentiate during the screen‐detectable phase and consequently screening with PSA and early treatment can possibly prevent dedifferentiation. © 2006 Wiley‐Liss, Inc.
Fast analysis in liquid chromatography using small particle size and high pressure
Authors: Nguyen Dao T.‐T. , Guillarme Davy , Rudaz Serge , Veuthey Jean‐Luc 
Published: July 2006

AbstractIn order to enhance chromatographic performances in terms of efficiency and rapidity, LC has recently evolved in the development of short columns packed with small particles (sub‐2 μm) working at high pressures (>400 bar). This approach has been described 30 years ago according to the fundamental chromatographic equations. However, systems and columns compatible with such high pressures have been introduced in the market in 2004 only. Advantages of small particles working at high pressure will be discussed in terms of sensitivity, efficiency, resolution, and analysis time. Potential problems encountered with high pressure in terms of frictional heating and solvent compressibility will also be discussed even if systems working at a maximum pressure of 1000 bar are not influenced by these parameters and give reliable and reproducible results. Several applications will highlight the potential and interest of this new technology.
Column selectivity for two‐dimensional liquid chromatography
Authors: Jandera Pavel 
Published: July 2006

AbstractSelectivity of phase system is of primary concern when designing a 2‐D separation, as it affects the 2‐D system orthogonality and consequently the peak capacity controlling the number of peaks that can be separated in the available 2‐D retention space limited by the time of analysis. Possibilities for characterization of LC phase system selectivity with respect to different polar and nonpolar structural units are compared, with special attention to multidimensional samples with various types of repeat groups, such as homopolymers, (co)polymers, fatty acid esters with various acyl lengths and number and position of double bonds, etc. Possibilities of the 2‐D LC separations of these and other sample types, including pharmaceuticals, natural phenolic compounds, biopolymers, etc., using various combinations of separation modes are reviewed. Rules for design of comprehensive 2‐D LC×LC systems are discussed, with respect to mobile phase compatibility in the two systems and modulation techniques suppressing band broadening connected with the sample fraction transfer from the first to the second dimension. Pitfalls connected with online connection of normal‐phase and RP LC systems and their possible practical solutions are addressed and illustrated by practical examples.
Regioregular Poly[3‐(4‐alkoxyphenyl)thiophene]s: Evidence for a Two‐Step Aggregation Process
Authors: Koeckelberghs Guy , Cornelis David , Persoons André , Verbiest Thierry 
Published: July 2006

AbstractSummary: A chiral, regioregular poly[3‐(4‐alkoxyphenyl)thiophene] has been prepared and studied. Films prepared by fast evaporation of the solvent, consist of random‐coils, while films prepared by slow evaporation are composed of chirally aggregated, coplanar strands. Heat treatment transforms the random‐coils into aggregated films via an intermediate state, which was characterized as chiral, coplanar, unaggregated polymer strands.Overview of the possible aggregation processes.magnified imageOverview of the possible aggregation processes.
Poly(diindenonaphthalene) and Poly(indenofluorene) – Tuning the Absorption Properties of Low Bandgap Cross‐Conjugated Polymers
Authors: Preis Eduard , Scherf Ullrich 
Published: July 2006

AbstractSummary: Semiconducting polymers with moderate HOMO–LUMO energy gaps between 1.5 and 2.0 eV are of increasing attraction as donor components of bulk heterojunction‐type organic solar cells. The synthesis and characterization of a novel cross‐conjugated, aromatic polymer, poly(diindenonaphthalene) PDIN, with a HOMO‐LUMO gap of ca. 1.6 eV (λmax: 724 nm) in comparison to poly(indenofluorene) PIF, a previously described, structurally related polymer, is presented. The replacement of the central benzene ring of PIF by a naphthalene moiety in PDIN leads to an increase of the optical bandgap energy of ca. 0.16 eV.Chemical structure of PIF and PDIN.magnified imageChemical structure of PIF and PDIN.
Novel Polyurethane Gels: The Effect of Structure on Gelation
Authors: Maiti Pralay , Radhakrishnan Ganga , Aruna Palanisamy , Ghosh Goutam 
Published: July 2006

AbstractNovel polyurethane gels have been reported in common solvent like dimethyl formamide (DMF). Polyurethanes have been synthesized from diisocyanates, diols and rigid chain extenders. We have illustrated the influence of chemical structure of the chain extenders on gelation rate, thermal property and morphology of the gels in DMF. Gelation rate increases significantly with the rigidity of the chain extender. Introduction of more rigid chain extender molecules in polyurethane prepolymer enhanced the thermal stability of the pure polymer. On the contrary, the solvent retention power of the gels gradually decreases with increasing rigidity of chain extender presumably because of the poor dispersion/greater aggregation of the hard segments in the soft segment matrix. Morphology and formation of gelation have been discussed.
The measurement of marketing efficiency in the presence of spillovers: theory and evidence
Authors: Vardanyan Michael , Tremblay Victor J. 
Published: July 2006

AbstractWe develop a model of marketing efficiency based on a directional distance function that allows for marketing spillovers. A parametric model is used to test for spillovers from rival marketing and from a firm's marketing activity of its other related products. We then show how this information can be incorporated into a non‐parametric model and used to estimate marketing inefficiency. We apply brand level data from the US brewing industry to the non‐parametric model to determine the effectiveness of television, radio, and print advertising. We find that advertising spillovers are important in brewing and show that efficiency estimates are inaccurate when spillover effects are ignored. Our results also suggest that marketing efficiency may be an important component to firm success in brewing, a result that may apply to other consumer goods industries. Copyright © 2006 John Wiley & Sons, Ltd.
The effect of communication in incentive systems—an experimental study
Authors: Harbring Christine 
Published: July 2006

AbstractIn organizational theory, it is a widely accepted postulate that cooperation among subjects is enforceable. This assumption is essential for the evaluation of two frequently discussed incentive systems: team and tournament compensation. Whereas in team‐based pay systems cooperation is highly desired, cooperation in rank‐order tournaments—labeled as ‘collusion’—is regarded as one of the main drawbacks of relative performance evaluation. In this experimental study, two different communication technologies are introduced into both incentive environments. The results indicate that when only limited communication is permitted subjects tend to cheat on each other in the tournament rather than in the team setting. Interestingly, allowing subjects to exchange emails leads to a similarly stable cooperation in both incentive systems. Copyright © 2006 John Wiley & Sons, Ltd.
Immediate early gene (ZENK) responses to song in juvenile female and male zebra finches: Effects of rearing environment
Authors: Tomaszycki Michelle L. , Sluzas Emily M. , Sundberg Kristy A. , Newman Sarah W. , DeVoogd Timothy J. 
Published: July 2006

AbstractAccurate song perception is likely to be as important for female songbirds as it is for male songbirds. Male zebra finches (Taeniopygia guttata) show differential ZENK expression to conspecific and heterospecific songs by day 30 posthatch in auditory perceptual brain regions such as the caudomedial nidopallium (NCM) and the caudomedial mesopallium (CMM). The current study examined ZENK expression in response to songs of different qualities at day 45 posthatch in both sexes. Normally reared juvenile zebra finches showed higher densities of immunopositive nuclei in both the dorsal and ventral areas of NCM and CMM (formerly cmHV), but not HA, a visual area, in response to normal song over untutored song or silence. Male and female patterns of ZENK expression did not differ. We next compared responses of birds reared without exposure to normal song (untutored) to those of normally reared birds. Untutored birds did not show higher responses to normal song than to untutored song in the three song perception areas. Furthermore, untutored birds of both sexes showed lower densities of immunopositive nuclei in all four areas than did normally reared birds. In addition, ZENK expression was greater in untutored females than in males in the dorsal portion of NCM and in CMM. Our findings suggest that at least some neural mechanisms of song perception are in place in socially reared female and male finches at an early age. Furthermore, early exposure to song tutors affects responses to song stimuli. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 1175–1182, 2006
A succession of anesthetic endpoints in the Drosophila brain
Authors: van Swinderen Bruno 
Published: July 2006

AbstractGeneral anesthetics abolish behavioral responsiveness in all animals, and in humans this is accompanied by loss of consciousness. Whether similar target mechanisms and behavioral endpoints exist across species remains controversial, although model organisms have been successfully used to study mechanisms of anesthesia. In Drosophila, a number of key mutants have been characterized as hypersensitive or resistant to general anesthetics by behavioral assays. In order to investigate general anesthesia in the Drosophila brain, local field potential (LFP) recordings were made during incremental exposures to isoflurane in wild‐type and mutant flies. As in higher animals, general anesthesia in flies was found to involve a succession of distinct endpoints. At low doses, isoflurane uncoupled brain activity from ongoing movement, followed by a sudden attenuation in neural correlates of perception. Average LFP activity in the brain was more gradually attenuated with higher doses, followed by loss of movement behavior. Among mutants, a strong correspondence was found between behavioral and LFP sensitivities, thereby suggesting that LFP phenotypes are proximal to the anesthetic's mechanism of action. Finally, genetic and pharmacological analysis revealed that anesthetic sensitivities in the fly brain are, like other arousal states, influenced by dopaminergic activity. These results suggest that volatile anesthetics such as isoflurane may target the same processes that sustain wakefulness and attention in the brain. LFP correlates of general anesthesia in Drosophila provide a powerful new approach to uncovering the nature of these processes. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 1195–1211, 2006
Negotiated representational mediators: How young children decide what to include in their science representations
Authors: Danish Joshua A. , Enyedy Noel 
Published: July 2006

AbstractIn this paper, we synthesize two bodies of work related to students' representational activities: the notions of meta‐representational competence and representation as a form of practice. We report on video analyses of kindergarten and first‐grade students as they create representations of pollination in a science classroom, as well as summarize results from interviews regarding the design choices that they made. Analysis of the semistructured pre‐ and postinterviews reveals that students attend to the content domain, local activity, and their personal preferences when evaluating representations. Analysis of video case studies that followed the students as they created their representations further reveals several key mediators of the students' representational activities, including other students, task constraints, the teacher, and local norms for what constituted a “good representation.” In addition, the data show that these norms shifted over time as new content was covered in the class, and were appropriated in interaction with other students. Finally, both sets of analyses reveal that students often face competing constraints when creating their representations, and resolve these constraints through a complex set of negotiations. © 2006 Wiley Periodicals, Inc.Sci Ed91:1–35, 2007
Greenland Ice Sheet History Since the Last Glaciation
Authors: Ten Brink Norman W. , Weidick Anker 
Published: July 2006

The position of the Inland Ice margin during the late Wisconsin-Würm glaciation (ca. 15,000 yr BP) is probably marked by offshore banks (submarine moraines?) in the Davis Strait. The history of the Inland Ice since the late Wisconsin-Würm can be divided into four principal phases: (1) Relatively slow retreat from the offshore banks occurred at an average rate of approximately 1 km/100 yr until ca. 10,000 yr BP (Younger Dryas?) when the Taserqat moraine system was formed by a readvance. (2) At ca. 9500 yr BP, the rate of retreat increased markedly to about 3 km/100 yr, and although nearly 100 km of retreat occurred by ca. 6500 yr BP, it was punctuated by frequent regional reexpansions of the Inland Ice that formed extensive moraine systems at ca. 8800-8700 yr BP (Avatdleq-Sarfartôq moraines), 8400-8100 yr BP (Angujârtorfik-Fjord moraines), 7300 yr BP (Umîvît moraines), and 7200-6500 yr BP (Keglen-Mt, Keglen moraines). (3) Between 6500 and 700 yr BP, discontinous ice-margin deposits and ice-disintegration features were formed during retreat, which may have continued until the ice margin was near or behind its present position by ca. 6000 yr BP. Most of the discontinuous ice-margin deposits occur within 5–10 km of the present ice margin, and may have been formed by two main phases of readvance at ca. 4800-4000 yr BP and 2500-2000 yr BP. (4) Since a readvance at ca. 700 yr BP, the Inland Ice margin has undergone several minor retreats and readvances resulting in deposition of numerous closely spaced moraines within about 3 km of the present ice margin. The young moraines are difficult to correlate regionally, but several individual moraines have the following approximate ages: A.D. 1650, 1750, and 1880–1920.Inland Ice fluctuations in West Greenland were very closely paralleled by Holocene glacial events in East Greenland and the eastern Canadian Arctic. Such similarity of glacier behavior over a large area strongly suggests that widespread climatic change was the direct cause of Holocene glacial fluctuations. Moreover, historical advances of the Inland Ice margin followed slight temperature decreases by no more than a few decades, and 18O data from Greenland ice cores show that slight temperature decreases occurred frequently throughout the Holocene. Therefore, we conclude that construction of the major Holocene moraine systems in West Greenland was caused by slight temperature decreases, which decreased rates of ablation and thereby produced practically immediate advances of the ice sheet margin, but did not necessarily affect the long-term equilibrium of the ice sheet.
An Anvilian (Early Pleistocene) Marine Fauna from Western Seward Peninsula, Alaska
Authors: Hopkins D.M. , Rowland R.W. , Echols R.E. , Valentine P.C. 
Published: July 2006

Cover sediments of the York Terrace exposed near the California River, western Seward Peninsula, Alaska, yield mollusks, ostracodes, and foraminifera that lived during the Anvilian transgression of early Pleistocene age. The fossiliferous sediments lie at the inner edge of the York Terrace, a deformed wave-cut platform that extends eastward from Bering Strait along much of the southern coast of Seward Peninsula. The seaward margin is truncated by the little-deformed Lost River Terrace, carved during the Pelukian (Sangamonian) transgression. The early Pleistocene sediments seem to have been deposited between the first and second of four glaciations for which evidence can be found in the California River area.The California River fauna includes several extinct species and several species now confined to areas as remote as the northwestern Pacific and north Atlantic. The fauna probably lived in water temperatures much like those of the present time but deeper water on the Bering Shelf is suggested.The presence of an early Pleistocene fauna at the inner edge of the York Terrace at California River shows that the terrace was largely carved before and during early Pleistocene time. However, a marine fauna apparently of middle Pleistocene age is found on the York Terrace near Cassiterite Peak, and this seems to indicate that the terrace remained low until middle Pleistocene time. Uplift of the York Terrace probably was accompanied by uplift of Bering Strait. The strait may have been deeper, and there may have been no land bridge between the Seward Peninsula of Alaksa and the Chukotka Peninsula of Siberia during most of early and middle Pleistocene time.
A Pollen Record from Birket Qarun and the Recent History of the Fayum, Egypt
Authors: Mehringer Peter J. , Petersen Kenneth L. , Hassan Fekri A. 
Published: July 2006

Sediments and fossil pollen of two short cores from Birket Qarun, Egypt, reflect Nile floods, lake levels, and agricultural developments of the last 325 yr, and demonstrate the potential of a long and detailed record from the Fayum Depression. The chronology of these cores is inferred by correlation of historic events with changes in the fossil and sedimentary records.Subangular clay clasts and blocky structure resulting from occasional exposure, drying, and reworking of lake sediments reflect low Nile floods of the mid-1600s. Abundant pollen of shallowwater, rooted aquatic plants provides evidence for continued low lake levels through the 1700s. A high lake level, resulting from the extreme Nile flood of 1817–1818, is recorded by hystrichospheres, reworked by wave action, from Eocene marine sediments exposed on the north shore of Birket Qarun.Political administration, as reflected in agricultural policy, is also recorded in lake history. Changing lake levels are, in part, correlated with canal neglect during Mamluk and Ottoman control, and renewed canal maintenance under the agricultural policy of Mohammed Ali. Increased cattail (Typha) pollen dates from perenial irrigation after 1873. Olive and date pollen, and pollen of newly introduced exotic trees, are abundant after 1930 as a result of accelerated introduction and cultivation of fruit, lumber, fuel, and windbreak trees following World War I. The sequence of introduction of exotic plants is reflected in the pollen ofZea mays, from the New World, followed byCasuarinafrom Southeast Asia and Australia, andEucalyptusfrom Australia.