bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation data corrections for snow‐covered sensors: are they needed for snowmelt modelling?
Authors: Melloh Rae A. , Hall Tommie J. , Bailey Ronald 
Published: April 2004

AbstractUp‐looking solar and atmospheric radiation sensors at remote and quasi‐remote weather stations are typically intermittently covered by snow in the winter. Numerous years of radiation data compromised in this way have been collected and archived at the Snow Research Station (SRS) in Danville, Vermont, and undoubtedly at numerous other research stations around the globe. Potential users of these archived data must question whether the data have value for their purpose, whether they can be corrected, what methods can be used to correct them, and perhaps most importantly, will time‐consuming correction efforts be justified by improved model performance. To answer these questions, both simple and elaborate methods of correcting incident solar and atmospheric radiation data were developed and applied to the 2001 snow season radiation data collected at the SRS. Snow‐affected incident solar radiation was estimated with reflected solar radiation measurements and either a simple albedo assumption or an albedo model. The equations of Idso, Brutsaert, Brunt, and Anderson and Baker were considered for correcting atmospheric radiation. The technique of Anderson and Baker was a good practical choice for this site, when used with a station offset, clearness index, and clear‐sky radiation model. Energy balance snowmelt calculations were made with SNTHERM, an internationally known and publicly available physically based snow process model. There was little justification for more than minimal corrections to radiation measurements for the presence of snow on radiation sensors when modelling snow depth, water equivalent, or melt efflux, because errors caused by snow‐covered solar and atmospheric radiation sensors largely offset one another. More elaborate efforts to correct both solar and atmospheric radiation data would be justified when correct quantification of individual snowpack energy components is important. Copyright © 2004 John Wiley & Sons, Ltd.
Prospective study of three major dietary patterns and risk of gastric cancer in Japan
Authors: Kim Mi Kyung , Sasaki Satoshi , Sasazuki Shizuka , Tsugane Shoichiro 
Published: April 2004

AbstractDietary pattern analysis is an alternative and complementary approach to identify the relationship between diet and the risk of chronic disease. This study was aimed at investigating the associations between dietary patterns and the risk of gastric cancer in Japan. Using baseline data from a prospective study of 20,300 men and 21,812 women, we conducted factor analysis and identified 3 major dietary patterns, healthy, traditional and Western, and calculated the factor scores of each pattern for individuals. During 10 years of follow‐up, 400 cases of gastric cancer were identified. We found an inverse association between the healthy pattern and gastric cancer risk in women [rate ratio for highest quartile (RR) = 0.56; 95% CI = 0.32–0.96; p for trend = 0.03], but not in men. In contrast, the traditional pattern was significantly associated with the increased risk of gastric cancer in both genders (for men, RR = 2.88, 95% CI = 1.76–4.72; for women, RR = 2.40, 95% CI = 1.32–4.35). The Western pattern was not associated with risk. These associations persisted in histologic subtypes. Our findings support the idea that the healthy pattern decreased the risk of gastric cancer among females, while the traditional pattern increased the risk in both genders. © 2004 Wiley‐Liss, Inc.
Distance, trade and FDI: a Hausman–Taylor SUR approach
Authors: Egger Peter , Pfaffermayr Michael 
Published: April 2004

AbstractThis paper analyses the effects of distance as a common determinant of exports and FDI in a three‐factor New Trade Theory model, assuming that distance affects both pure trade costs and plant set‐up costs. Exports and FDI are not necessarily substitutes with respect to distance, since the predicted impact depends on its importance for fixed plant set‐up costs relative to transportation costs and on the relative importance of vertical MNEs. For the empirical specification, we suggest that the impact of time‐invariant variables such as distance is most appropriately analysed in a Hausman–Taylor SUR model. We apply our model to industry‐level data of bilateral outward FDI stocks and exports of the US and Germany. Copyright © 2004 John Wiley & Sons, Ltd.
More powerful panel data unit root tests with an application to mean reversion in real exchange rates
Authors: Smith L. Vanessa , Leybourne Stephen , Kim Tae‐Hwan , Newbold Paul 
Published: April 2004

AbstractUnit root tests, seeking mean or trend reversion, are frequently applied to panel data. We show that more powerful variants of commonly applied tests are readily available. Moreover, power gains persist when the modifications are applied to bootstrap procedures that may be employed when cross‐correlation of a rather general sort among individual panel members is suspected. Copyright © 2004 John Wiley & Sons, Ltd.
Sequence‐specific potentiation of topoisomerase II inhibitors by the histone deacetylase inhibitor suberoylanilide hydroxamic acid
Authors: Marchion Douglas C. , Bicaku Elona , Daud Adil I. , Richon Victoria , Sullivan Daniel M. , Munster Pamela N. 
Published: April 2004

AbstractAcetylation of histones leads to conformational changes of DNA. We have previously shown that the histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA), induced cell cycle arrest, differentiation, and apoptosis. In addition to their antitumor effects as single agents, HDAC inhibitors may cause conformational changes in the chromatin, rendering the DNA more vulnerable to DNA damaging agents. We examined the effects of SAHA on cell death induced by topo II inhibitors in breast cancer cell lines. Topo II inhibitors stabilize the topo II–DNA complex, resulting in DNA damage. Treatment of cells with SAHA promoted chromatin decondensation associated with increased nuclear concentration and DNA binding of the topo II inhibitor and subsequent potentiation of DNA damage. While SAHA‐induced histone hyperacetylation occurred as early as 4 h, chromatin decondensation was most profound at 48 h. SAHA‐induced potentiation of topo II inhibitors was sequence‐specific. Pre‐exposure of cells to SAHA for 48 h was synergistic, whereas shorter pre‐exposure periods abrogated synergy and exposure of cells to SAHA after the topo II inhibitor resulted in antagonistic effects. Synergy was not observed in cells with depleted topo II levels. These effects were not limited to specific types of topo II inhibitors. We propose that SAHA significantly potentiates the DNA damage induced by topo II inhibitors; however, synergy is dependent on the sequence of drug administration and the expression of the target. These findings may impact the clinical development of combining HDAC inhibitors with DNA damaging agents. © 2004 Wiley‐Liss, Inc.
Retinoic acid regulates the expression of PBX1, PBX2, and PBX3 in P19 cells both transcriptionally and post‐translationally
Authors: Qin Pu , Haberbusch Juliet M. , Soprano Kenneth J. , Soprano Dianne Robert 
Published: April 2004

AbstractPre‐B cell leukemia transcription factors (PBXs) are important co‐factors for the transcriptional regulation mediated by a number of Hox proteins during embryonic development. It was previously shown that the expression of several Pbx genes is elevated in mouse embryo limb buds and embryonal carcinoma P19 cells upon retinoic acid (RA) treatment although the mechanism of this induction is not well understood. In this report, we demonstrate that PBX1a, PBX1b, PBX2, and PBX3 mRNAs and PBX1/2/3 proteins are induced during endodermal and neuronal differentiation of P19 cells in a RAR‐dependent subtype‐unspecific manner following RA treatment. The increases in both PBX1 mRNA and PBX3 mRNA levels are secondary responses to RA treatment requiring new proteins synthesis while the increase in PBX2 mRNA is a primary response. The RA‐dependent increases in PBX1 mRNA, PBX2 mRNA, and PBX3 mRNA levels are likely to be transcriptionally regulated since the stability of these mRNAs does not change. In addition, the half‐lives of PBX1/2/3 proteins are significantly extended by RA treatment. Two possible mechanisms could contribute to the stabilization of PBX proteins: PBX proteins associate with RA‐dependent increased levels of MEIS proteins, and RA may decrease the proteasome dependent degradation of PBX proteins. © 2004 Wiley‐Liss, Inc.
Inactivated tumor suppressor Rb by nitric oxide promotes mitosis in human breast cancer cells
Authors: Radisavljevic Ziv 
Published: April 2004

AbstractInactivation of tumor suppressor protein retinoblastoma (Rb) is important mechanism for the G1/S transition during cell cycle progression. Human breast cancer cells T47D release great amount of nitric oxide (NO), but its relation to tumor suppressor Rb is unknown. In this study, it is shown that NO induces phosphorylation and inactivation of Rb tumor suppressor protein, increasing G2/M phase and cell proliferation of breast cancer cells T47D. NO did not induce changes in p53 ser‐15 phosphorylation, the most phosphorylated site of p53 during its activation. These data indicate that NO induces cell proliferation through the Rb pathway. NO phosphorylates and inactivates tumor suppressor protein Rb inducing mitosis by the p53 independent pathway in breast cancer cell. © 2004 Wiley‐Liss, Inc.
Civic responsibility among Australian adolescents: Testing two competing models
Authors: Silva Lisa da , Sanson Ann , Smart Diana , Toumbourou John 
Published: April 2004

AbstractThe development of civic responsibility is considered to be an important component of healthy adolescent development. However, the study of its development has been relatively neglected and few studies have attempted to ground understanding of its development in a theoretical framework. The present study operationalized civic responsibility as attitudes and behaviors relating to political and community issues that are beneficial to society and compared two theoretical causal models, the social development model (SDM) and a coping‐competency model for their predictive value. Gender differences were also assessed. A total of 500 subjects, drawn from a longitudinal study (the Australian Temperament Project), participated in the study, using questionnaire and interview data. Approximately 1 in 5 adolescents actively engaged in behaviors reflecting community civic responsibility and less than 1 in 10 actively participated in the political arena. However, positive levels of social awareness were evident. Hierarchical multiple regression analyses indicated that the SDM had the most predictive value for political and community civic responsibility. Peer encouragement and peer participation were the most significant predictors. Variables from the coping‐competency model played some role in the prediction of community, but not political, civic responsibility. Gender differences in community civic responsibility, but not political civic responsibility, were found. One in two adolescents indicated that they would participate in volunteer work or political activities if more opportunities existed. This suggests the need for greater availability of appropriate community‐oriented activities for adolescents. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 229–255, 2004.
The impact of community health workers on the self‐determination, self‐sufficiency, and decision‐making ability of low‐income women and mothers of young children
Authors: Kovach Andrea Crivelli , Becker Julie , Worley Heidi 
Published: April 2004

AbstractPregnant women at high risk for adverse health outcomes can benefit from the services of community health workers. Maternity Care Coalition identifies at risk women and provides links to health care and social services through the MOMobile Program. The purpose of this study was to explore (a) the relationship formed between community health workers and pregnant women, and (b) the change over time in a mother's perceived level of empowerment as measured by self‐sufficiency, self‐determination, and decision‐making skills. A multiphase study was developed to collect data. Focus group interviews with community health workers explored their professional role, their relationship with mothers, and the meaning of decision‐making, self‐sufficiency, and self‐determination as empowerment constructs. A questionnaire was developed to measure each construct at two points in time. A pilot study with 80 women was conducted. Scores for each construct and overall empowerment were calculated and the pre‐ and post‐scores compared to measure change over time. Results of paired t‐tests showed significant differences between the postpartum mean score for decision‐making (P < .01), self‐sufficiency (P < .01), self‐determination (P < .001), and overall empowerment (P < .001) and the mean scores on each construct at registration. Results suggest that empowerment can be operationalized in community settings and that increasing an at risk pregnant woman's sense of empowerment may positively impact the overall health of the mother and child. Further research is needed to assess the full impact of this variable as a health status indicator. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 343–356, 2004.
Angiopoietin‐2 enhances retinal vessel sensitivity to vascular endothelial growth factor
Authors: Oshima Yuji , Deering Tye , Oshima Sachiko , Nambu Hiroyuki , Reddy P. Seshidhar , Kaleko Michael , Connelly Sheila , Hackett Sean F. , Campochiaro Peter A. 
Published: April 2004

AbstractIncreased expression of vascular endothelial growth factor (VEGF) in the retina starting after postnatal day (P)7 results in neovascularization originating from deep retinal capillaries, but not those in the superficial capillary bed. Doxycycline was administered starting P0 to double transgenic mice with inducible expression of VEGF in the retina. These mice showed proliferation and dilation of superficial retinal capillaries, indicating that at this stage of development, the superficial capillaries are sensitive to the effects of VEGF. Angiopoietin‐2 (Ang2) is expressed along the surface of the retina for several days after birth, but by P7 and later, Ang2 is only expressed in the region of the deep capillary bed. In mice with ubiquitous doxycycline‐inducible expression of Ang2, in the absence of doxycycline, intravitreous injection of a gutless adenoviral vector expressing VEGF (AGV.VEGF) resulted in neovascularization of the cornea and iris, but no retinal neovascularization. After treatment with doxycycline to induce Ang2 expression, intravitreous injection of AGV.VEGF caused retinal neovascularization in addition to corneal and iris neovascularization. The retinal neovascularization originated from both the superficial and deep capillary beds. These data suggest that Ang2 promotes sensitivity to the angiogenic effects of VEGF in retinal vessels. © 2004 Wiley‐Liss, Inc.
Na+/Mg2+ exchange is functionally coupled to the insulin receptor
Authors: Ferreira Ana , Rivera Alicia , Romero José R. 
Published: April 2004

AbstractRegulation of cellular Mg2+ levels by insulin has been shown in various tissues. However, the mechanisms for hormonal regulation of cellular Mg2+ have not been well described. We studied the effect of insulin on Na+/Mg2+ exchange in normal human cells, measuring Na+/Mg2+ exchange activity as net total Mg2+ efflux driven by an inward Na+ gradient in Mg2+‐loaded red blood cells (RBCs). Na+/Mg2+ exchange was increased significantly by the addition of 2.4 nmol/L of insulin to the flux medium (from 0.60 ± 0.06 mmol/L cell × h to 0.75 ± 0.08 mmol/L cell × h [P = 0.0098, n = 44]). A dose‐response curve for the effects of insulin on the exchanger activity gave an estimated EC50 for insulin of 0.95 ± 0.31 nmol/L and a Vmax of 0.86 ± 0.12 mmol/L cell × h (n = 7). Kinetics of the Na+/Mg2+ exchange were characterized by measuring its activity as a function of Mg2+ and Na+ concentrations. The K0.5 for cellular Mg2+ was not affected by incubation with insulin. However, the K0.5 for extracellular Na+ decreased from 69.9 ± 6.3 to 40.3 ± 8.4 mol/L (n = 5, P = 0.03) in the presence of insulin. We also studied the effect of wortmannin (WT), a PI 3‐kinase inhibitor, on activity of the exchanger. WT significantly blocked the insulin‐stimulated Na+/Mg2+ activity (n = 6, P = 0.048), with an IC50 of 0.5 nmol/L. LY294002, another PI 3‐kinase inhibitor, likewise blocked the insulin‐stimulated activity of the exchanger. Therefore, insulin regulates cellular Mg2+ metabolism in part via an increase in the affinity for Na+ of the Na+/Mg2+ exchange and PI 3‐kinase activation, suggesting another role for the PI 3‐kinase pathway in insulin‐mediated cellular events. © 2003 Wiley‐Liss, Inc.
Inducible expression of a MAP kinase phosphatase‐3‐GFP chimera specifically blunts fibroblast growth and ras‐dependent tumor formation in nude mice
Authors: Marchetti S. , Gimond C. , Roux D. , Gothié E. , Pouysségur J. , Pagès Gilles 
Published: April 2004

AbstractThe p42/p44 mitogen activated protein kinase (MAPK) pathway participates in a wide range of cellular programs including proliferation, migration, differentiation, and survival. Specific pharmacological inhibitors, like PD98059 and U0126, are often used to inhibit p42/p44 MAPK signaling. However, these inhibitors are not appropriate to study the function of these kinases in whole organisms. We thus developed an inducible system designed to inhibit p42/p44 MAPK activity through the expression of a phosphatase specific for these two kinases, the MAPK phosphatase 3 (MKP‐3). A fibroblast cell line was established in which MKP‐3 expression is controlled by tetracycline. Tetracycline‐induced MKP‐3 resulted in partial de‐phosphorylation of p42/p44 MAPKs in serum‐stimulated cells. However, we could improve MKP‐3 stability and thereby the rate of MAPK de‐phosphorylation, when the C‐terminal end of MKP‐3 was fused to the green fluorescent protein (GFP). Importantly, the fusion of GFP to MKP‐3 did not alter the specificity of the phosphatase towards its MAPK substrates. We further show that conditional expression of MKP‐3‐GFP in this fibroblast cell line results in the inhibition of: (a) the phosphorylation of the p42/p44 MAPK substrates Elk1 and HIF‐1α, (b) vascular endothelial growth factor (VEGF), cyclin D1, and c‐fos gene transcription in response to MAPK pathway activation, and (c) cell proliferation. Finally, the MKP‐3‐GFP inducible cell line was transformed by Ha‐ras and injected into nude mice. Treatment of mice with the tetracycline analog doxycycline resulted in a large delay in tumor emergence and growth as compared to the untreated control group, indicating that MKP‐3‐GFP activity is maintained in vivo. Altogether, these results show that inducible expression of MKP‐3‐GFP constitutes a valuable tool to study the role of p42/p44 MAPKs in various cellular responses in both cultured cell and animal models, a tool that may also be used to block unwanted cell growth in pathological conditions. © 2004 Wiley‐Liss, Inc.
VEGF‐R2 and neuropilin‐1 are involved in VEGF‐A‐induced differentiation of human bone marrow progenitor cells
Authors: Fons Pierre , Herault Jean‐Pascal , Delesque Nathalie , Tuyaret Joēl , Bono Françoise , Herbert Jean‐Marc 
Published: April 2004

AbstractTumor growth and metastasis require the generation of new blood vessels, a process known as neo‐angiogenesis. Recent studies have indicated that early tumor vascularization is characterized by the differentiation and mobilization of human bone marrow cells. Vascular endothelial growth factor‐A (VEGF‐A) is one of the growth factors, which enhances their differentiation into endothelial cells, but little is known about the implication of the VEGF‐receptor tyrosine kinases and about the implication of the VEGF‐R co‐receptor, neuropilin‐1, in this process. In this context, the identification of the molecular pathways that support the proliferation and differentiation of vascular stem and progenitor cells was investigated in order to define the pharmaceutical targets involved in tissue vascularization associated with this process. For this purpose, an in vitro model of differentiation of human bone marrow AC133+ (BM‐AC133+) cells into vascular precursors was used. In this work, we have demonstrated for the first time that the effect of VEGF‐A on BM‐AC133+ cells relies on an early action of VEGF‐A on the expression of its tyrosine kinase receptors followed by an activation of a VEGF‐R2/neuropilin‐1‐dependent signaling pathway. This signaling promotes the differentiation of BM‐AC133+ cells into endothelial precursor cells, followed by the proliferation of these differentiated cells. Altogether, these results strongly suggest that VEGF inhibitors, acting at the level of VEGF‐R2 and/or neuropilin‐1, by inhibiting differentiation and proliferation of these cells, could be potentially active compounds to prevent progenitor cells to be involved in tumor angiogenesis leading to tumor growth. © 2004 Wiley‐Liss, Inc.
Vertex‐disjoint cycles containing specified vertices in a bipartite graph
Authors: Chen Guantao , Enomoto Hikoe , Kawarabayashi Ken‐ichi , Ota Katsuhiro , Lou Dingjun , Saito Akira 
Published: April 2004

AbstractA minimum degree condition is given for a bipartite graph to contain a 2‐factor each component of which contains a previously specified vertex. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 145–166, 2004
A Gallai–Edmonds‐type structure theorem for path‐matchings
Authors: Spille Bianca , Szegő László 
Published: April 2004

AbstractAs a generalization of matchings, Cunningham and Geelen introduced the notion of path‐matchings. We give a structure theorem for path‐matchings which generalizes the fundamental Gallai–Edmonds structure theorem for matchings. Our proof is purely combinatorial. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 93–102, 2004
Regular 4‐critical graphs of even degree
Authors: Dobrynin Andrey A. , Melnikov Leonid S. , Pyatkin Artem V. 
Published: April 2004

AbstractIn 1960, Dirac posed the conjecture that r‐connected 4‐critical graphs exist for every r ≥ 3. In 1989, Erdős conjectured that for every r ≥ 3 there exist r‐regular 4‐critical graphs. In this paper, a technique of constructing r‐regular r‐connected vertex‐transitive 4‐critical graphs for even r ≥ 4 is presented. Such graphs are found for r = 6, 8, 10. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 103–130, 2004
Chloride transport in the vegetative mycelia of filamentous fungus Trichoderma viride
Authors: Šimkovič M. , Pokorný R. , Hudecová D. , Varečka Ľ. 
Published: April 2004

AbstractThe influx of chlorides into Trichoderma viride vegetative submerged mycelium was measured by means of the radionuclide 36Cl−. It was found that the 36Cl− influx was time‐dependent (the steady‐state was established with t1/2 = 25 min at 25 °C), pH‐dependent (with pH optimum between 4–5.5), temperature‐dependent (at about 15 °C), and concentration‐dependent (KM = 47.6 ± 4.2 μmol · l−1; Jmax = 11.5 ± 0.7 pmol(Cl−) · min−1 · mgdry mass−1). The 36Cl− influx was inhibited by Br− but not F−, I−, SO42−, HPO32− and HCO3−. The presence of vanadate (P‐type ATPase inhibitor) moderately stimulated the 36Cl− influx but the presence valinomycin (electrogenic K+ ionophore), salicylate (known to release Ca2+ from Trichoderma viride internal stores) were without effect on the 36Cl− influx. The results suggest that the 36Cl− influx is mediated by a carrier and that the transport is electroneutral, probably Cl−/OH− antiport. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)