bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the role of topography in small channel erosion
Authors: Santisteban L. M. De , Casalí J. , López J. J. , Giráldez J. V. , Poesen J. , Nachtergaele J.
Published: April 2005

Erosion caused by concentrated flows in agricultural areas is responsible for important soil losses, and rapid sediment transfer through the channel network. The main factors controlling concentrated flow erosion rates include the erodibility of soil materials, soil use and management, climate and watershed topography. In this paper, two topographic indices, closely related to mathematical expressions suggested by different authors, are used to characterize the influence of watershed topography on gully erosion. The AS1 index is defined as the product of the watershed area and the partial area‐weighted average slope. The AS2 index is similar to the AS1 but uses the swale slope as the weighting factor. Formally, AS2 is the product of the watershed area and the length‐weighted average swale slope. From studies made using different ephemeral gully erosion databases, it is shown that a high correlation consistently exists between the topographic indices and the volume of eroded soil. The resulting relationships are therefore useful to assess soil losses from gully erosion, to identify the most susceptible watersheds within large areas, and to compare the susceptibility to gully erosion among different catchments. This information is also important in studying the response of natural drainage network systems to different rainfall inputs. Copyright © 2005 John Wiley & Sons, Ltd.
Modelling the effect of waves, weathering and beach development on shore platform development
Authors: Trenhaile A. S.
Published: April 2005

A mathematical model was used to study shore platform development. Mechanical wave erosion was dependent on such variables as tidal range, wave height and period, breaker height and depth, breaker type, surf zone width and bottom roughness, submarine gradient, rock resistance and the elevational frequency of wave action within the intertidal zone. Also included were the effects of sand and pebble accumulation, cliff height and debris mobility, and downwearing associated with tidal wetting and drying. The occurrence, location and thickness of beaches often depended on initially quite minor variations in platform morphology, but owing to their abrasive or protective effect on underlying rock surfaces, they were able to produce marked differences in platform morphology. Generalizations are difficult, but the model suggests that platform gradient increases with tidal range. Platform width also increases with tidal range with slow downwearing but it decreases with fast downwearing. Platform gradient decreases and width increases with wave energy, and decreasing rock resistance and platform roughness. With low tidal range, platform gradient is generally lower and platform width greater with beaches of fine sand than with gravel, but the relationship is more variable with a high tidal range. Platform width increases and platform gradient decreases with the rate of downwearing on bare surfaces, particularly in low tidal range environments, but the pattern is less clear on beach‐covered platforms. Platforms with large amounts of beach sediment tend to be narrower and steeper than bare platform surfaces. Platform gradient increases and platform width decreases with increasing cliff height and with decreasing cliff debris mobility. Copyright © 2005 John Wiley & Sons, Ltd.
Blanket peat erosion and sediment yield in an upland reservoir catchment in the southern Pennines, UK
Authors: Yeloff D. E. , Labadz J. C. , Hunt C. O. , Higgitt D. L. , Foster I. D. L.
Published: April 2005

This paper investigates temporal variations in fluxes of peat and other sediment in the catchment of March Haigh Reservoir, West Yorkshire. Long‐term estimates of sediment yield were derived from a study of reservoir sediments. Magnetic properties were used to correlate ten cores to a master profile dated using 210Pb and 137Cs. A 14C date suggests that most of the organic component of the sediment is allochthonous and derived from peat eroded from the catchment. Organic sediment yields suggest low catchment erosion rates between 1838 and 1963. Blanket peat erosion increased significantly after 1963, and peaked between 1976 and 1984. Estimates of total sediment yield range between 2 and 28 t km−2 a−1. These yields are significantly lower than those from some previous studies examining reservoir sedimentation in other blanket peat‐covered catchments. The low yield estimates may be due to relatively low rates of erosion in the basin, but may also be partly explained by maintenance of silt traps during the early life of the reservoir and removal of sediment by scouring. Sedimentation within the reservoir is spatially variable, and bathymetry and sediment source appear to be the dominant controls on sedimentation patterns within the reservoir. Copyright © 2005 John Wiley & Sons, Ltd.
Vortex shedding from a square cylinder in presence of a moving wall
Authors: Bhattacharyya S. , Maiti D. K.
Published: April 2005

A numerical study on the flow past a square cylinder placed parallel to a wall, which is moving at the speed of the far field has been made. Flow has been investigated in the laminar Reynolds number (based on the cylinder length) range. We have studied the flow field for different values of the cylinder to wall separation length. The governing unsteady Navier–Stokes equations are discretized through the finite volume method on a staggered grid system. A SIMPLE type of algorithm has been used to compute the discretized equations iteratively. A shear layer of negative vortex generates along the surface of the wall, which influences the vortex shedding behind the cylinder. The flow‐field is distinct from the flow in presence of a stationary wall. An alternate vortex shedding occurs for all values of gap height in the unsteady regime of the flow. The strong positive vortex pushes the negative vortex upwards in the wake. The gap flow in the undersurface of the cylinder is strong and the velocity profile overshoots. The cylinder experiences a downward force for certain values of the Reynolds number and gap height. The drag and lift are higher at lower values of the Reynolds number. Copyright © 2005 John Wiley & Sons, Ltd.
A simple algebraic interface capturing scheme using hyperbolic tangent function
Authors: Xiao F. , Honma Y. , Kono T.
Published: April 2005

This paper presents a simple and practical scheme for capturing moving interfaces or free boundaries in multi‐fluid simulations. The scheme, which is called THINC (tangent of hyperbola for interface capturing), makes use of the hyperbolic tangent function to compute the numerical flux for the fluid fraction function, and gives a conservative, oscillation‐less and smearing‐less solution to the fluid fraction function even for the extremely distorted interfaces of arbitrary complexity. The numerical results from the THINC scheme possess adequate quality for practical applications, which make the extra geometric reconstruction, such as those in most of the volume of fluid (VOF) methods unnecessary. Thus the scheme is quite simple. The numerical tests show that the THINC scheme has competitive accuracy compared to most exiting methods. Copyright © 2005 John Wiley & Sons, Ltd.
Impaired capacity for upregulation of MHC class II in tumor‐associated microglia
Authors: Schartner Jill M. , Hagar Aaron R. , Van Handel Michelle , Zhang Leying , Nadkarni Nivedita , Badie Behnam
Published: April 2005

Immunotherapy for malignant gliomas is being studied as a possible adjunctive therapy for this highly fatal disease. Thus far, inadequate understanding of brain tumor immunology has hindered the design of such therapies. For instance, the role of microglia and macrophages, which comprise a significant proportion of tumor‐infiltrating inflammatory cells, in the regulation of the local anti‐tumor immune response is poorly understood. To study the response of microglia and macrophages to known activators in brain tumors, we injected CpG oligodeoxynucleotide (ODN), interferon‐γ (IFN‐γ), and IFN‐γ/LPS into normal and intracranial RG2 glioma‐bearing rodents. Microglia/macrophage infiltration and their surface expression of MHC class II B7.1 and B7.2 was examined by flow cytometry. Each agent evaluated yielded a distinct microglia/macrophage response: CpG ODN was the most potent inducer of microglia/macrophage infiltration and B7.1 expression, while IFN‐γ resulted in the highest MHC‐II expression in both normal and tumors. Regardless of the agent injected, however, MHC‐II induction was significantly muted in tumor microglia/macrophage as compared with normal brain. These data suggest that microglia/macrophage responsiveness to activators can vary in brain tumors when compared with normal brain. Understanding the mechanism of these differences may be critical in the development of novel immunotherapies for malignant glioma. © 2005 Wiley‐Liss, Inc.
Pattern of cannabis use in ecstasy polydrug users: moderate cannabis use may compensate for self‐rated aggression and somatic symptoms
Authors: Milani R. M. , Parrott A. C. , Schifano F. , Turner J. J. D.
Published: April 2005

Cannabis is one of the most common ‚co‐drugs’︁ for ecstasy users. The aim of the present study was to explore self‐reported psychobiological problems in ecstasy polydrug users in relation to their pattern of cannabis use. Two hundred and eighty ecstasy polydrug users were allocated into five cannabis groups according to the frequency of their cannabis use. The control group comprised 121 alcohol‐tobacco users. There were no significant group differences with regard to age, diagnosed family psychiatric history and level of self‐rated stress experienced during 6 months prior to the study. The present study produced three main findings: (a) Ecstasy users with no concomitant use of cannabis displayed more self‐rated aggression and somatic symptoms compared with ecstasy users who were smoking cannabis on a monthly or weekly basis. (b) Ecstasy users who reported heavy cannabis use in the past displayed higher paranoid symptoms compared with ecstasy weekly and daily cannabis users. (c) Former heavy cannabis users were the most likely to complain of a variety of ecstasy related long‐term problems. In conclusion, moderate cannabis use may help to ameliorate or mask MDMA‐induced aggressivity and somatic symptoms. However, this study confirms that heavy cannabis and ecstasy use is associated with several psychobiological problems, which may emerge after a period of abstinence from both drugs. Copyright © 2005 John Wiley & Sons, Ltd.
Transactivation of cyclin E gene by EWS‐Fli1 and antitumor effects of cyclin dependent kinase inhibitor on Ewing's family tumor cells
Authors: Li Xu , Tanaka Kazuhiro , Nakatani Fumihiko , Matsunobu Tomoya , Sakimura Riku , Hanada Masuo , Okada Takamitsu , Nakamura Tomoyuki , Iwamoto Yukihide
Published: April 2005

Chromosomal translocation t(11; 22)(q24; q12) is detected in approximately 90% of Ewing's family tumors (EFTs) including Ewing's sarcoma and primitive neuroectodermal tumor. This results in the formation of the EWS‐Fli1 fusion gene, which produces EWS‐Fli1 fusion protein. This chimerical gene product acts as an aberrant transcriptional activator, which may be responsible for the tumorigenesis of EFTs. We have previously reported that cyclin E expression was upregulated in EFT cells and in EWS‐Fli1 transformed fibroblastic cells. However, the mechanism of the overexpression of cyclin E by EWS‐Fli1 is still unknown. In our study, we investigated the mechanism of transactivation of the cyclin E gene in EFT cells. We found that EWS‐Fli1 enhanced the activity of the cyclin E gene promoter partially through E2F binding sites in the promoter. In addition, the basic transcriptional factor, Sp1, might also be involved in the transactivation of the cyclin E gene by EWS‐Fli1. To study the biological significance of cyclin E overexpression in EFT cells, we used flavopiridol, a pan‐cyclin‐dependent kinase (CDK) inhibitor and found that flavopiridol efficiently suppressed the growth of EFT cells in vitro and in vivo by the inhibition of cyclinE/CDK2 kinase activity and the induction of apoptosis. These results suggest that targeting of the cyclin/CDK complex may provide new insight into treatment of EFTs. © 2005 Wiley‐Liss, Inc.
hTERT gene copy number is not associated with hTERT RNA expression or telomerase activity in colorectal cancer
Authors: Palmqvist Richard , Zhang Anju , Xu Dawei , Golovleva Irina , Norrback Karl‐Fredrik , Gruber Astrid , Öberg Åke , Stenling Roger , Roos Göran
Published: April 2005

In a majority of malignant human tumors telomerase activity can be detected, suggesting an immortal phenotype. Expression of the reverse transcriptase subunit, hTERT, in the human telomerase complex is required for telomerase activity. The regulation of hTERT, from gene level to a fully functional protein, is still a poorly understood process. Increased copy number of the hTERT gene has been demonstrated in a significant portion of established cell lines and tumors of different origin but its relevance for telomerase activity levels is unclear. In the present study, we examined the hTERT gene copy number using fluorescence in situ hybridization (FISH) in samples from 64 colorectal carcinomas and an increased copy number (≥ 3 hTERT gene copies/nucleus) was observed in 31 cases (48%). No statistical association existed between hTERT gene copy number and hTERT RNA expression or telomerase activity. However, a significant relationship was found between an increase in hTERT gene copy number and p53 protein accumulation (p = 0.002) and aneuploidy (p = 0.036). Only 4 tumors showed microsatellite instability, 3 of which had a normal hTERT gene copy number. The data indicated that the increased copy number of the hTERT gene in colorectal carcinoma was a result of genomic instability with no obvious consequence for telomerase activity levels. © 2005 Wiley‐Liss, Inc.
Endogenous immune response to gangliosides in patients with confined prostate cancer
Authors: Ravindranath Mepur H. , Muthugounder Sakunthala , Presser Naftali , Ye Xing , Brosman Stanley , Morton Donald L.
Published: April 2005

Our study investigated whether endogenous IgM antibodies to gangliosides occur in patients with early stages of prostate cancer (CaP) patients, after defining ganglioside profiles of CaP cell lines. Immune and resorcinol staining detected the presence of gangliosides GM3, GM2, GD3, GD2 and GD1a but not GM1a, GD1b or GT1b in the extracts of normal prostatic epithelial cells (PrEC) and neoplastic androgen‐insensitive (PC‐3, DU145) and ‐sensitive (LNCaP‐FGC and LNCaP‐FGC‐10) CaP cells. Using a sensitive ELISA, developed and validated in our laboratory, the titers of IgM against 8 gangliosides from sera of patients with benign prostatic hyperplasia (BPH) (n = 11), organ‐confined (T1/T2, n = 36) and unconfined (T3/T4, n = 27) CaP and age‐matched healthy men (n = 11) were determined double‐blinded. Using ANOVA and Fisher's least significant difference (LSD) methods, the log‐titers among different groups were compared. CaP patients differed from healthy and BPH patients in increased titers against GD1a and decreased titers against GD3. Titers of antibodies to other gangliosides exhibited no difference between CaP patients and others. The specific augmentation of anti‐GD1a IgM in patients with organ‐confined CaP (stage T1/T2) but not in patients with unconfined CaP (stage T3/T4) or BPH or in healthy controls is striking. This finding together with identification of GD1a as a major ganglioside in CaP cell lines and with the accruing studies on the immunosuppressive nature of GD1a indicates that augmentation of anti‐GD1a IgM in confined CaP may signify an early endogenous immune response to eliminate a “danger signal” from tumor microenvironment and circulation. © 2005 Wiley‐Liss, Inc.
Epidemiology of testicular cancer: An overview
Authors: Garner Michael J. , Turner Michelle C. , Ghadirian Parviz , Krewski Daniel
Published: April 2005

Testicular cancer is a rare disease, accounting for 1.1% of all malignant neoplasms in Canadian males. Despite the low overall incidence of testicular cancer, it is the most common malignancy among young men. The incidence rate of testicular cancer has been increasing since the middle of the 20th century in many western countries. However, the etiology of testicular cancer is not well understood. A search of the peer‐reviewed literature was conducted to identify important articles for review and inclusion in this overview of the epidemiology of testicular cancer. Most of the established risk factors are related to early life events, including cryptorchidism, carcinoma in situ and in utero exposure to estrogens. Occupational, lifestyle, socioeconomic and other risk factors have demonstrated mixed associations with testicular cancer. Although there are few established risk factors for testicular cancer, some appear to be related to hormonal balance at various life stages. Lifestyle and occupational exposures occurring later in life may play a role in promoting the disease, although they are not likely involved in cancer initiation. In addition to summarizing the current epidemiologic evidence on risk factors for testicular cancer, we suggest future research directions that may elucidate the etiology of testicular cancer. © 2005 Wiley‐Liss, Inc.
Family history as a co‐factor for adenocarcinoma and squamous cell carcinoma of the uterine cervix: Results from two studies conducted in Costa Rica and the United States
Authors: Zelmanowicz Alice de M. , Schiffman Mark , Herrero Rolando , Goldstein Alisa M. , Sherman Mark E. , Burk Robert D. , Gravitt Patti , Viscidi Ray , Schwartz Peter , Barnes Willard , Mortel Rodrigue , Silverberg Steven G. , Buckland Julie , Hildesheim Allan
Published: April 2005

Previous work suggests that cervical cancer may aggregate in families. We evaluated the association between a family history of gynecological tumors and risk of squamous cell and adenocarcinomas of the cervix in 2 studies conducted in Costa Rica and the United States. The Costa Rican study consisted of 2,073 women (85 diagnosed with CIN3 or cancer, 55 diagnosed with CIN2 and 1,933 controls) selected from a population‐based study of 10,049 women. The U.S. study consisted of 570 women (124 with in situ or invasive adenocarcinomas, 139 with in situ or invasive squamous cell carcinomas of the cervix and 307 community‐based controls) recruited as part of a multicentric case‐control study in the eastern part of the United States. Information on family history of cervical and other cancers among first‐degree relatives was ascertained via questionnaire. Information on other risk factors for cervical cancer was obtained via questionnaire. Human papillomavirus (HPV) exposure was assessed in both studies using broad spectrum HPV L1‐based PCR testing of exfoliated cervicovaginal cells and in Costa Rica by additional testing of plasma collected from participants for antibodies against the L1 protein of HPV types 16, 18, 31 and 45 by ELISA. A family history of cervical cancer in a first‐degree relative was associated with increased risk of squamous tumors in both studies (odds ration [OR] = 3.2 for CIN3/cancer vs. controls; 95% confidence interval [CI] = 1.1–9.4 in Costa Rica; OR = 2.6 for in situ/invasive squamous cell carcinoma cases vs. controls, 95% CI = 1.1–6.4 in the Eastern United States study). These associations were evident regardless of whether the affected relative was a mother, sister or daughter of the study participant. Furthermore, observed effects were not strongly modified by age. In Costa Rica, the effect persisted in analysis restricted to HPV‐exposed individuals (OR = 3.0; 95% CI = 1.0–9.0), whereas in the Eastern United States study there was evidence of attenuation of risk in analysis of squamous carcinoma cases restricted to HPV positive women (OR = 1.4; 95% CI = 0.29–6.6). No significant association was observed between a family history of cervical cancer in a first‐degree relative and adenocarcinomas (OR = 1.3; 95% CI = 0.43–3.9). History of gynecological tumors other than cervical cancer in a first‐degree relative was not significantly associated with risk of disease in either study. These results are consistent with a role of host factors in the pathogenesis of squamous cell cervical cancer, although familial aggregation due to shared environmental exposures cannot be ruled out. © 2005 Wiley‐Liss, Inc.
Intracellular anti‐E7 human antibodies in single‐chain format inhibit proliferation of HPV16‐positive cervical carcinoma cells
Authors: Accardi Luisa , Donà M. Gabriella , Di Bonito Paola , Giorgi Colomba
Published: April 2005

The E7 tumor antigen of human papillomavirus type 16 (HPV16) is a validated target for immunodiagnosis and immunotherapy of HPV‐associated cervical cancer. Anti‐HPV16 E7 antibodies in scFv format were isolated from a human antibody phage display library and characterized. With the aim of interfering with the oncogenic activity of E7 protein, the most reactive of the selected antibody fragments was expressed by eukaryotic vectors in different compartments of the HPV16‐positive cervical carcinoma SiHa cell line. The intracellular antibodies (intrabodies) were tested for their ability of inhibiting cell proliferation. A significant inhibition was obtained targeting the intrabodies to the nuclear and secretory compartments whereas no significant effect was observed in case of cytoplasmic localization. Inhibition was highly specific as no antiproliferative effect was obtained either with the E7‐specific intrabodies in HPV‐negative cells nor with irrelevant intrabodies in SiHa cells. © 2005 Wiley‐Liss, Inc.
Identification of 20 genes aberrantly methylated in human breast cancers
Authors: Miyamoto Kazuaki , Fukutomi Takashi , Akashi‐Tanaka Sadako , Hasegawa Tadashi , Asahara Toshimasa , Sugimura Takashi , Ushijima Toshikazu
Published: April 2005

Aberrant methylation of CpG islands (CGI) not only plays a role in gene silencing, but is also a potential cancer biomarker. To identify more CGI aberrantly methylated in human breast cancers, we carried out a genome‐wide search for aberrant methylation, using methylation‐sensitive‐representational difference analysis. CGI in 5′ upstream regions of 20 genes, TSPAN‐2, AK5, LOC284999, HOXD11, FLJ25161, XT3, PCDH10, PCDHGB6, SIM1, LOC346978, COE2, TDH (FLJ25033), LOC346419, FLJ33790, GJB2, AMN, LOC201164, DLX4, DCC and FOXA2, were found to be methylated in at least one of 8 breast cancer cell lines. Fifteen of the 20 genes were methylated in more than one of 21 primary breast cancers in Stages I or II, and especially, those of LOC346978, HOXD11, SIM1, PCDHGB6 and FLJ25161 were methylated in more than 10 cancers. All the breast cancers had some aberrant methylation. Among the 13 genes whose CGI were completely methylated in one or more cell lines, FOXA2 and XT3 were expressed in normal human mammary epithelial cells (HMEC) and were not expressed in cancer cell lines with complete methylation. The other 11 genes examined were barely expressed, or not expressed even in HMEC. Our results showed that breast cancer cells accumulate aberrant methylation of the CGI identified here. This may serve as markers for early‐stage breast cancers and suggests that aberrant methylation targets transcriptionally inactive genes in vivo. © 2005 Wiley‐Liss, Inc.
Serum matrix metalloproteinase‐9 in head and neck squamous cell carcinomais a prognostic marker
Authors: Ruokolainen Henni , Pääkkö Paavo , Turpeenniemi‐Hujanen Taina
Published: April 2005

The aim of this study was to determine whether serum matrix metalloproteinase‐9 (MMP‐9) could predict cause‐specific and relapse‐free survival in patients with squamous cell carcinoma of head and neck. Furthermore, this study was designed to investigate whether there is an association between MMP‐9 immunohistochemical staining and serum MMP‐9 levels. Pretreatment serum levels of MMP‐9 were quantitatively measured by ELISA assay in 67 patients presenting with a primary head and neck squamous cell carcinoma. The results were compared with the corresponding immunohistochemical staining results, clinical data and the patients' outcome. The follow‐up time for all of the patients was at least 5 years. There was a statistically significant correlation between circulating MMP‐9 and MMP‐9 immunohistochemical staining in the corresponding tumors (p = 0.028). The cause‐specific and relapse‐free survival rates were clearly lower among patients with high MMP‐9 serum levels (> 73 ng/ml). The 5‐year cause‐specific survival‐rate was 40% in a patient group with high serum MMP‐9, and 69% for patients with a low MMP‐9 level (p = 0.027). In the same follow‐up period, the cumulative relapse‐free survival rate was 36% in patients presenting with a high serum MMP‐9 and 66% in those with a low MMP‐9 level. No correlation was found between MMP‐9 serum levels and the traditional clinical or histopathologic factors. The results suggest for the first time that pretreatment serum MMP‐9 level could serve as a prognostic factor in head and neck squamous cell carcinoma. © 2005 Wiley‐Liss, Inc.
Ribonucleotide reductase inhibitors enhance cidofovir‐induced apoptosis in EBV‐positive nasopharyngeal carcinoma xenografts
Authors: Wakisaka Naohiro , Yoshizaki Tomokazu , Raab‐Traub Nancy , Pagano Joseph S.
Published: April 2005

In nasopharyngeal carcinoma (NPC), Epstein‐Barr virus (EBV) infection is mainly latent, and the tumor cells contain episomal viral DNA. We have shown that the acyclic nucleoside phosphonate analog, cidofovir [(S)‐1‐(3‐hydroxy‐2‐(phosphonylmethoxypropyl))cytosine] (HPMPC), inhibits growth of NPC xenografts in nude mice by causing apoptosis. The ribonucleotide reductase (RR) inhibitors, hydroxyurea and didox (3,4‐dihydroxybenzohydroxamic acid), have been demonstrated to inhibit neoplastic growth and are used as antiviral and anticancer agents. Here we show that RR inhibitors enhance the antitumor effect of cidofovir in EBV‐transformed epithelial cells. MTT assays indicate that hydroxyurea and didox enhance cidofovir‐induced cell toxicity in NPC‐KT cells, an EBV‐positive epithelial cell line derived from NPC. The effect is due to enhancement of apoptosis through the caspase cascade as shown by pronounced cleavage of poly(ADP‐ribose) polymerase. Finally, hydroxyurea strikingly enhanced the cidofovir‐induced growth‐inhibitory effect on NPC grown in athymic mice. The results suggest that RR inhibitors should enhance the antitumor effect of acyclic nucleoside phosphonate analogs on NPC. © 2005 Wiley‐Liss, Inc.
Zori 1.0: A parallel quantum Monte Carlo electronic structure package
Authors: Aspuru–Guzik Alán , Salomón–Ferrer Romelia , Austin Brian , Perusquía–Flores Raul , Griffin Mary A. , Oliva Ricardo A. , Skinner David , Domin Dominik , Lester William A.
Published: April 2005

The Zori 1.0 package for electronic structure computations is described. Zori performs variational and diffusion Monte Carlo computations as well as correlated wave function optimization. This article presents an overview of the implemented methods and code capabilities. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 856–862, 2005
Hamiltonicity and forbidden subgraphs in 4‐connected graphs
Authors: Pfender Florian
Published: April 2005

Let T be the line graph of the unique tree F on 8 vertices with degree sequence (3,3,3,1,1,1,1,1), i.e., T is a chain of three triangles. We show that every 4‐connected {T, K1,3}‐free graph has a hamiltonian cycle. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 262–272, 2005
Posets and planar graphs
Authors: Felsner Stefan , Trotter William T.
Published: April 2005

Usually dimension should be an integer valued parameter. We introduce a refined version of dimension for graphs, which can assume a value [t − 1 ↕ t], thought to be between t − 1 and t. We have the following two results: (a) a graph is outerplanar if and only if its dimension is at most [2↕3]. This characterization of outerplanar graphs is closely related to the celebrated result of W. Schnyder [16] who proved that a graph is planar if and only if its dimension is at most 3. (b) The largest n for which the dimension of the complete graph Kn is at most [t − 1 ↕ t] is the number of antichains in the lattice of all subsets of a set of size t − 2. Accordingly, the refined dimension problem for complete graphs is equivalent to the classical combinatorial problem known as Dedekind's problem. This result extends work of Hoşten and Morris [14]. The main results are enriched by background material, which links to a line of research in extremal graph theory, which was stimulated by a problem posed by G. Agnarsson: Find the maximum number of edges in a graph on n nodes with dimension at most t. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 273–284, 2005
Nitrogen mineralization from mature bio‐waste compost in vineyard soils II. Test of N‐mineralization parameters in a long‐term in situ incubation experiment
Authors: Nendel Claas , Reuter Stephan , Kersebaum Kurt Christian , Kubiak Roland , Nieder Rolf
Published: April 2005

A field incubation experiment was carried out to test the applicability of N‐mineralization parameters for mature bio‐waste compost for use in a simulation model. The parameters were previously obtained from a laboratory experiment. Micro‐lysimeters were used for incubation, containing four different vineyard soils that were treated with three different compost‐application rates (0, 30, and 50 Mg compost ha–1). Between 2.0% and 45.2% of total bio‐waste compost N was mineralized and leached from the micro‐lysimeters during the two‐year investigation period. The application of a simulation model for soil N dynamics revealed two major drawbacks of the model: (1) in most of the soils, extraordinary high mineralization rates were observed within a few weeks after compost amendment, which could not be explained by the model, and (2) the average compost‐N‐mineralization rates were estimated as being close to the observed rates (–6%), but distinct deviations in some cases (–46% to +29%) led to considerable miscalculations in long‐term simulations. Excluding the effect of these two processes from the data set, the remaining variance could be well explained by the model for all soils treated with compost (modeling efficiency ≥0.98). Based on the average performance, the mineralization parameters for mature bio‐waste compost are considered to be applicable for use in any simulation model based on the double‐exponential approach for calculating fertilizer recommendations, whereas the functions calculating the impact of environmental factors on N mineralization in the model need to be revised. The initial mineralization flush observed in most of the compost treatments was attributed to a priming effect. The experiment showed that such a priming effect can cause exceptionally high rates of N mineralization from mature bio‐waste compost in a viticultural environment, which exceed the potential mineralization rates known for bio‐waste compost applied to arable soils in Germany.
Evidence‐based medical review update: Pharmacological and surgical treatments of Parkinson's disease: 2001 to 2004
Authors: Goetz Christopher G. , Poewe Werner , Rascol Olivier , Sampaio Cristina
Published: April 2005

The objective of this study is to update a previous evidence‐based medicine (EBM) review on Parkinson's disease (PD) treatments, adding January 2001 to January 2004 information. The Movement Disorder Society (MDS) Task Force prepared an EBM review of PD treatments covering data up to January 2001. The authors reviewed Level I (randomized clinical trials) reports of pharmacological and surgical interventions for PD, published as full articles in English (January 2001–January 2004). Inclusion criteria and ranking followed the original program and adhered to EBM methodology. For Efficacy Conclusions, treatments were designated Efficacious, Likely Efficacious, Non‐Efficacious, or Insufficient Data. Four clinical indications were considered for each intervention: prevention of disease progression; treatment of Parkinsonism, as monotherapy and as adjuncts to levodopa where indicated; prevention of motor complications; treatment of motor complications. Twenty‐seven new studies qualified for efficacy review, and others covered new safety issues. Apomorphine, piribedil, unilateral pallidotomy, and subthalamic nucleus stimulation moved upward in efficacy ratings. Rasagiline, was newly rated as Efficacious monotherapy for control of Parkinsonism. New Level I data moved human fetal nigral transplants, as performed to date, from Insufficient Data to Non‐ efficacious for the treatment of Parkinsonism, motor fluctuations, and dyskinesias. Selegiline was reassigned as Non‐efficacious for the prevention of dyskinesias. Other designations did not change. In a field as active in clinical trials as PD, frequent updating of therapy‐based reviews is essential. We consider a 3‐year period a reasonable time frame for published updates and are working to establish a Web‐based mechanism to update the report in an ongoing manner. © 2005 Movement Disorder Society
Steady compressible Navier–Stokes equations in domains with non‐compact boundaries
Authors: Novo S. , Novotný A. , Pokorný M.
Published: April 2005

We consider the steady compressible Navier–Stokes equations of isentropic flow in three‐dimensional domains with several exits to infinity with prescribed pressure drops. On the one hand, when each exit is supposed to contain a cone inside, we shall construct bounded energy weak solution for adiabatic constantγ>3. On the other hand, when the exits do not open sufficiently rapidly, we shall prove a non‐existence result. Copyright © 2005 John Wiley & Sons, Ltd.
The dachshund gene is required for the proper guidance and branching of mushroom body axons in Drosophila melanogaster
Authors: Martini Sharyl R. , Davis Ronald L.
Published: April 2005

The dachshund gene encodes a transcription factor required for the proper development of Drosophila eyes, legs, and mushroom bodies. The mushroom bodies of dachshund mutants exhibit a marked reduction in the size of the vertical lobes and disorganization of the horizontal lobes. In mosaic animals, mutant axons fail to contribute significantly to the mushroom body α lobe. Here we show that this defect is due to the misrouting of αβ axons to the region normally occupied by α′β′ axons. This defect is pronounced for clones generated in larval stages but not clones generated after pupariation, indicating that dachshund function is particularly important around the time of puparium formation. In addition, mushroom body axons exhibit excessive branching in dachshund mutant clones. Thus, dachshund is required in mushroom body neurons for proper axon guidance and branching. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Seasonal‐like plasticity of spontaneous firing rate in a songbird pre‐motor nucleus
Authors: Park Kevin H. J. , Meitzen John , Moore Ignacio T. , Brenowitz Eliot A. , Perkel David J.
Published: April 2005

Many animals exhibit seasonal changes in behavior and its underlying neural substrates. In seasonally breeding songbirds, the brain nuclei that control song learning and production undergo substantial structural changes at the onset of each breeding season, in association with changes in song behavior. These changes are largely mediated by photoperiod‐dependent changes in circulating concentrations of gonadal steroid hormones. Little is known, however, about whether changes in the electrophysiological activity of neurons accompany the dramatic morphological changes in the song nuclei. Here we induced seasonal‐like changes in the song systems of adult white‐crowned sparrows and used extracellular recording in acute brain slices from those individuals to study physiological properties of neurons in the robust nucleus of the arcopallium (RA), a pre‐motor nucleus necessary for song production. We report that: RA neurons from birds in breeding condition show a more than twofold increase in spontaneous firing rate compared to those from nonbreeding condition; this change appears to require both androgenic and estrogenic actions; and this change is intrinsic to the RA neurons. Thus, neurons in the song circuit exhibit both morphological and physiological adult seasonal plasticity. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Fundamental boron–oxygen‐related carrier lifetime limit in mono‐ and multicrystalline silicon
Authors: Bothe Karsten , Sinton Ron , Schmidt Jan
Published: April 2005

Boron‐doped crystalline silicon is the most relevant material in today's solar cell production. Following the trend towards higher efficiencies, silicon substrate materials with high carrier lifetimes are becoming more and more important. In silicon with sufficiently low metal impurity concentrations, the carrier lifetime is ultimately limited by a metastable boron–oxygen‐related defect, which forms under minority‐carrier injection. We have analysed 49 different Czochralski‐grown silicon materials of numerous suppliers with various boron and oxygen concentrations. On the basis of our measured lifetime data, we have derived a universal empirical parameterisation predicting the stable carrier lifetime from the boron and oxygen content in the crystalline silicon material. For multicrystalline silicon it is shown that the predicted carrier lifetime can be regarded as a fundamental upper limit. Copyright © 2005 John Wiley & Sons, Ltd.
Photovoltaic power plant experience at Arizona Public Service: a 5‐year assessment
Authors: Moore L. , Post H. , Hayden H. , Canada S. , Narang D.
Published: April 2005

Arizona Public Service (APS) currently has over 4·9 MWdc of grid‐connected photovoltaic systems that have been installed in its service territory over the past five years. Most of this installed PV capacity is in support of the Arizona Corporation Commission Environmental Portfolio Standard goal that encourages APS to generate 1·1% of its energy generation through renewable resources by 2007, with 60% of that amount from solar. During this time, much has been learned regarding performance, cost, maintenance, installation and design. This paper presents an assessment of these topics and a perspective associated with this PV experience. Published in 2005 by John Wiley & Sons, Ltd.
Poly(epichlorohydrin) modified with 3,4,5‐tris(dodecyloxy)benzoate: The structure and dynamics of the aliphatic side chains in the columnar mesophase
Authors: Giamberini Marta , Ronda Joan Carles , Reina José Antonio
Published: April 2005

We investigated the dynamics and structure of the aliphatic side chains of a randomly grafted copolymer, obtained through the chemical modification of poly(epichlorohydrin) with potassium 3,4,5‐tris(dodecyloxy)benzoate, with solid‐state 13C NMR. Below 283 K, the aliphatic chains partially crystallized in an all‐anti conformation. The calorimetric data were compatible with an orthorhombic packing. Below 323 K, the polymer exhibited a columnar mesophase. Spin–lattice relaxation times were determined in this temperature range and at 333 K, that is, in the isotropic phase. In the liquid‐crystalline state, some carbons exhibited a double decay in the spin–lattice relaxation, and this was attributed to presence of the liquid‐crystalline phase. This hypothesis was supported by a conformational analysis performed by molecular modeling. The activation energies of the relaxation processes in the mesophase were also estimated. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2099–2111, 2005
Dependence of the pretreatment efficiency of polymer‐based adsorbents for environmental water on their uniformity and size
Authors: Kubo Takuya , Hosoya Ken , Watabe Yoshiyuki , Tanaka Nobuo , Sano Tomoharu , Kaya Kunimitsu
Published: April 2005

Polymer‐based adsorbents with excellent size uniformity were used as pretreatment media for real environmental water containing numerous contaminants. A comparison of the results with those from an ideal approach with high‐performance liquid chromatography suggested that the shape size and size uniformity of the adsorbents were very important with respect to the loading pressure for the treatment of the environmental water. Furthermore, one of the uniformly sized polymer adsorbents realized an efficiency comparable to that of a commercially available adsorbent based on a typical silica‐based octadecyl stationary phase. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2112–2118, 2005
Electronic and structural properties of orthorhombic KTiOPO4 and related isomorphic materials
Authors: Lowther J. E. , Manyum P. , Suebka P.
Published: April 2005

Ab‐initio electronic structure calculations using the local density (LDA) and generalized gradient approximations (GGA) are undertaken on Potassium Titanyl Phosphate (KTP) and isomorphic materials. The crystal structure is better predicted using one of the GGA approximations. The affect of Rb replacing K on the essential TiO6 and PO4 blocks of the alloyed system are investigated as are affects of AsO4 replacing PO4. It is observed that the asymmetry in the K–Rb alloy very slightly affects the electronic properties of the material. Electronic charge density distributions clearly show the cation conduction channels, with changes found to occur between the different structural isomorphs. A calculated density of electronic states shows the importance of Ti–O interactions around the Fermi energy that lead to important laser properties. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum Monte Carlo approach to the Holstein polaron problem
Authors: Hohenadler Martin , Evertz Hans Gerd , von der Linden Wolfgang
Published: April 2005

A recently developed quantum Monte Carlo approach to the Holstein model with one electron [Phys. Rev. B 69, 024301 (2004)] is extended in several aspects. In addition to a straight‐forward generalization to higher dimensions, a checkerboard breakup for the hopping part of the Hamiltonian is introduced, which allows significantly faster simulations. Moreover, results are extrapolated towards the limit of continuous imaginary time to remove the error due to the Trotter–Suzuki approximation. The performance and accuracy of the current approach are compared to existing quantum Monte Carlo methods. To demonstrate the applicability of our method for almost arbitrary parameters, we study the small‐polaron crossover in one to three dimensions by calculating the electronic kinetic energy. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of selenium telluride glass
Authors: Mauro John C. , Varshneya Arun K.
Published: April 2005

We develop model interaction potentials for the heterogeneous selenium–tellurium system based on ab initio molecular simulations and a cluster expansion technique. The model potentials are used in classical Monte Carlo simulations to characterize the structure of SeTe glass in the canonical ensemble. The simulated structure is in good qualitative agreement with available experimental data.

1. Computed structure of SeTe glass (20 Å × 20 Å × 20 Å subset). The smaller (gray) atoms are selenium, and the larger (blue) atoms are tellurium. The SeTe glass consists of homopolar Se and Te chains with very little heteropolar bonding.

image

1. Computed structure of SeTe glass (20 Å × 20 Å × 20 Å subset). The smaller (gray) atoms are selenium, and the larger (blue) atoms are tellurium. The SeTe glass consists of homopolar Se and Te chains with very little heteropolar bonding.

(© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The vibrational structure of the OH radical in solid argon: A transfer‐matrix path‐integral approach
Authors: Costa Cabral B. J.
Published: April 2005

The vibrational structure of the hydroxyl radical in argon was investigated by transfer‐matrix path‐integral calculations. The results for the OH X2Π ground state in Ar indicate that the vibrational structure in the matrix is modified relative to the gas phase. However, only vibrational levels above v = 12 are significantly perturbed. The changes of the higher vibrational energy levels can be explained by interactions between the OH radical and the Ar matrix. We predict that the position of the OH fundamental in argon matrix is 3540 cm−1 in good agreement with the experimental result (3548.2 cm−1). This value is red‐shifted by ∼6 cm−1 relative to the free radical (3546 cm−1). In contrast with previous results for Br2 in solid Ar, where a very large barrier related to confinement effects inhibits dissociation, the present study indicates that the OH radical can dissociate in the matrix. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Study of peptide on‐line complexation with transition‐metal ions generated from sacrificial electrodes in thin‐chip polymer microsprays
Authors: Rohner Tatiana C. , Girault Hubert H.
Published: April 2005

A miniaturized polymer electrospray‐type interface is used to study metal‐ion chelation with model peptides. Taking advantage of the intrinsic electrochemical behavior of electrospray, a sacrificial electrode is used to generate at the same time electrospray and transition‐metal ions coming from the anodic dissolution of the electrode. The microspray interface provides enhanced mass transport due to its small dimensions, increasing the yield of possible reactions, in particular complex formation. Transition‐metal electrodes, e.g. copper, zinc, nickel, iron and silver, are used to obtain on‐line complexation with model peptides. It is demonstrated that the use of in‐reservoir sacrificial electrodes is an efficient way to generate metal ions in order to form and study complexes with peptides, avoiding the addition of metallic salts. Copyright © 2005 John Wiley & Sons, Ltd.
Doppler‐derived umbilical artery absolute velocities and their relationship to fetoplacental volume blood flow: a longitudinal study
Authors: Acharya G. , Wilsgaard T. , Berntsen G. K. R. , Maltau J. M. , Kiserud T.
Published: April 2005

Objectives

To construct reference ranges for serial measurements of the umbilical artery (UA) absolute blood flow velocities in the second half of pregnancy and to test the hypothesis that significant associations exist between UA velocities and placental volume blood flow assessed from umbilical vein blood flow velocities and diameter.

Methods

This was a prospective longitudinal study of the umbilical circulation. UA absolute velocities and umbilical vein blood flow were measured at 4‐weekly intervals between 19 and 42 weeks' gestation in 130 low‐risk singleton pregnancies. A total of 511 observations were used to construct the reference ranges and assess the association between UA absolute velocities and placental volume flow using multilevel modeling.

Results

Both UA absolute velocities and placental volume blood flow showed a steady increase throughout the second half of pregnancy. However, the gestational age‐related increase in the UA end‐diastolic velocity (EDV) was greater than the corresponding increase in the peak systolic velocity (PSV). The time‐averaged intensity‐weighted mean velocity (TAWMV)/time‐averaged maximum velocity (TAMXV) was 0.6 indicating probably not a completely parabolic velocity profile. There was a significant positive association (P < 0.00001) between UA absolute velocities and placental volume blood flow, but this association was modified by the gestational age. The intraobserver coefficients of variation for the UA PSV, EDV, TAMXV and TAWMV and placental volume blood flow were 10.17%, 16.29%, 11.46%, 18.18% and 8.61%, respectively.

Conclusion

We have established new reference ranges for the UA absolute velocities based on longitudinal data. They show a significant association with fetoplacental volume blood flow and may have a clinical value in the assessment of the umbilical circulation. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.