bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of gene expression changes induced in mouse and human cells treated with direct‐acting mutagens
Authors: Islaih Mohammed , Li Baohui , Kadura Ibrahim A. , Reid‐Hubbard Jaclyn L. , Deahl J. Thom , Altizer Julie L. , Watson David E. , Newton Ronald K.
Published: November 2004

Exposure to DNA‐damaging agents can elicit a variety of stress‐related responses that may alter the gene expression of numerous biological pathways. We used Affymetrix microarrays to detect gene expression changes in mouse lymphoma (L5178Y) and human lymphoblastoid (TK6) cells in response to methyl methanesulfonate (MMS; a prototypical alkylating agent) and bleomycin (a prototypical oxidative mutagen). Cells were treated for 4 hr, and RNA was isolated either at the end of the treatment or after a 20‐hr recovery period. Two concentrations of each agent were used based on cytotoxicity levels and Tk mutant frequencies. Our microarray data analysis indicated that MMS and bleomycin gene expression responses were considerably different in mouse cells versus human cells. The results also suggested that more comprehensive cellular responses to MMS and bleomycin occurred in TK6 cells than in L5178Y cells. In contrast to L5178Y cells, the response of TK6 cells to MMS and bleomycin was characterized by the induction of p53‐dependent genes that are involved in DNA repair, cell cycle regulation, and apoptosis. It appears that the induction of DNA damage by MMS in human TK6 cells mediated cytotoxicity and led to decreased cell survival. This may explain the greater sensitivity of TK6 cells to cytotoxic effects of MMS compared to L5178Y cells. Bleomycin exerted comparable cytotoxic effects in the two cell lines. Overall, these studies were unable to identify distinctive gene expression changes that differentiated bleomycin from MMS in either TK6 cells or mouse lymphoma cells. Environ. Mol. Mutagen. 2004. © 2004 Wiley‐Liss, Inc.
Calibration of gas chromatography inlet splitting for gas chromatography olfactometry dilution analysis
Authors: Deibler Kathryn D. , Martin Llesca Fabien , Lavin Edward H. , Acree Terry E.
Published: November 2004

The application of solid phase microextraction (SPME) to gas chromatography–olfactometry (GC–O) dilution analysis has previously been achieved by varying the thickness of the ﬁbre phase and the length of exposure. In this study, eight steps of dilution by a factor of 2 were achieved by splitting of the injected sample in different ratios in the gas chromatograph's injection port. Using solvent injection and SPME headspace sampling, it was found that the nominal split ratios of the hardware requires calibration to achieve the actual dilutions desired. This calibration method was applied to the CharmAnalysis of coffee as it was brewed. Copyright © 2004 John Wiley & Sons, Ltd.
In vivo studies on the long‐term persistence of volatiles in the breath
Authors: Hodgson M. , Parker A. , Linforth R. S. T. , Taylor A. J.
Published: November 2004

The long‐term persistence of ﬁve volatiles in the breath was studied to determine the effects of respiration and the physical properties of each of the volatiles. The long‐term persistence of each of the volatiles in the breath was modelled successfully and used to show that the breath volatile concentration 1 min after consuming the solution was greater when panelists exhaled at a slower rate. The air–water partition coefﬁcient (Kaw) was inﬂuential in controlling the initial stages of persistence; compounds with a higher Kaw were found to decay at a much faster rate than compounds with a low Kaw. The decay rate during the later stages was constant for all the volatiles, which indicates that the rate‐limiting factor during the later stages of persistence does not depend on the individual properties of the volatiles. Copyright © 2004 John Wiley & Sons, Ltd.
Comparison between orthonasal and retronasal ﬂavour perception at different concentrations
Authors: Espinosa Diaz Marian
Published: November 2004

To be perceived, ﬂavour molecules need to reach the olfactory epithelium, located in the nasal cavity. This can be achieved through orthonasal (sniff) or retronasal (mouth) airways. The intensity perceived will depend on the number of molecules that reach the receptor cells. The aim of this study is to compare the dose–response behaviour of ﬂavour molecules, depending on whether the ﬂavours were sniffed or tasted. Six ﬂavour compounds were studied, including a homologous series of esters, and the differences on dose–response curves (intensity vs. concentration) correlated to the physicochemical characteristics of the ﬂavour molecules. In addition, the matching concentration in water to get the same intensity by sniff as a reference tasted by mouth for some ﬂavour compounds was determined. It was shown that the differences in orthonasal and retronasal perception depend strongly on the physical characteristics of the aroma chemicals. Copyright © 2004 John Wiley & Sons, Ltd.
Physical characterization of controlled release of paclitaxel from the TAXUS™ Express2™ drug‐eluting stent
Authors: Ranade Shrirang V. , Miller Kathleen M. , Richard Robert E. , Chan A. Ken , Allen Michael J. , Helmus Michael N.
Published: November 2004

The polymer carrier technology in the TAXUS™ drug‐eluting stent consists of a thermoplastic elastomer poly(styrene‐b‐isobutylene‐b‐styrene) (SIBS) with microphase‐separated morphology resulting in optimal properties for a drug‐delivery stent coating. Comprehensive physical characterization of the stent coatings and cast film formulations showed that paclitaxel (PTx) exists primarily as discrete nanoparticles embedded in the SIBS matrix. Thermal and chemical analysis did not show any evidence of solubility of PTx in SIBS or of any molecular miscibility between PTx and SIBS. Atomic force microscope data images revealed for the first time three‐dimensional stent coating surfaces at high spatial resolutions in air and in situ under phosphate‐buffered saline as drug was released. PTx release involves the initial dissolution of drug particles from the PTx/SIBS coating surface. Morphological examination of the stent coatings in vitro supported an early burst release in most formulations because of surface PTx followed by a sustained slower release of PTx from the bulk coating. The in vitro PTx release kinetics were dependent on the formulation and correlated to the drug‐to‐polymer ratio. Atomic force microscopy analysis confirmed this correlation and further supported the concept of a matrix‐based drug‐release coating. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 625–634, 2004
Paradigmatic identification of MMP‐2 and MT1‐MMP activation systems in cardiac fibroblasts cultured as a monolayer
Authors: Guo Chun , Jiang Juwei , Martin Elliott J. , Piacentini Lucia
Published: November 2004

Activations of MMP‐2 and membrane type 1‐matrix metalloproteinase (MT1‐MMP) have been correlated with cell migration, a key cellular event in the wound healing and tissue remodeling. We have previously demonstrated furin‐dependent MMP‐2 and MT1‐MMP activations induced by type I collagen in cardiac fibroblasts. To understand mechanistic aspects of the regulation of MMP‐2 and MT1‐MMP activations by potential non‐matrix factor(s) in cardiac fibroblasts, in the present study, we examined the effects of various agents including concanavalin A (ConA), a proteolytic phenotype‐producing agent. We showed that treatment of cells with ConA activated pro‐MMP‐2, and that this activation concurred with elevated levels of cellular MT1‐MMP and TIMP‐2. The presence of active MT1‐MMP and 43 and 36 kDa processed forms of MT1‐MMP in a fraction of intracellular proteins prepared from ConA‐treated cells suggests the possible internalization of differential forms of MT1‐MMP. The appearance of 36 kDa processed form of MT1‐MMP in conditioned media prepared from ConA‐treated cells indicates the possible extracellular release of the further processed MT1‐MMP fragment. Inhibition of furin in ConA‐treated cells attenuated pro‐MT1‐MMP processing and the cellular TIMP‐2 level, plus it reduced cell‐released active MMP‐2 in a time‐dependent manner. These results suggest the involvement of furin in the ConA‐induced activations of MT1‐MMP and MMP‐2. Furthermore, the existence of furin inhibitor‐insensitive pro‐ and active MMP‐2 species associated with ConA‐treated cells implies that a mechanism independent of furin may perhaps account for the binding of the MMP‐2 species to the cells. Supplementary material for this article can be found at http://www.mrw.interscience.wiley.com/suppmat/0730‐2312/suppmat/94/suppmat_guo.tif. © 2004 Wiley‐Liss, Inc.
High hydrostatic pressure inhibits the biosynthesis of eukaryotic elongation factor‐2
Authors: Elo Mika A. , Karjalainen Hannu M. , Sironen Reijo K. , Valmu Leena , Redpath Nicholas T. , Browne Gareth J. , Kalkkinen Nisse , Helminen Heikki J. , Lammi Mikko J.
Published: November 2004

High continuous hydrostatic pressure is known to inhibit the total cellular protein synthesis. In this study, our goal was to identify pressure‐regulated proteins by using two dimensional gel electrophoresis and mass spectrometry. This analysis showed that under 30 MPa continuous hydrostatic pressure the biosynthesis of eukaryotic elongation factor‐2 (eEF‐2) was inhibited both in HeLa carcinoma and T/C28a4 chondrocytic cell lines. Western blot analysis of HeLa cells revealed that the cellular protein level of eEF‐2 decreased by 40%–50% within 12 h of the pressure treatment. However, the steady‐state mRNA level of eEF‐2 was not affected by the pressure. Cycloheximide addition after 4 h‐pressure treatment suggested that the half‐life of eEF‐2 protein was shorter in pressurized cells. eEF‐2 is responsible for the translocation of ribosome along the specific mRNA during translation, and its phosphorylation prevents the ribosomal translocation. Therefore, increased phosphorylation of eEF‐2 was considered as one mechanism that could explain the reduced level of protein synthesis in pressurized HeLa cell cultures. However, Western blot analysis with an antibody recognizing the Thr56‐phosphorylated form of eEF‐2 showed that phosphorylation of eEF‐2 was not elevated in pressurized samples. In conclusion, the inhibition of protein synthesis under high pressure occurs independent of the phosphorylation of eEF‐2. However, this inhibition may result from the decrease of cellular eEF‐2 protein. © 2004 Wiley‐Liss, Inc.
No 17‐player triplewhist tournament has nontrivial automorphisms
Authors: Haanpää Harri
Published: November 2004

The existence of triplewhist tournaments for v players has recently been solved for all values of v except  = 17. For v = 12 and v = 13, a complete enumeration has shown the nonexistence of TWh(v), while constructions of TWh(v) have been presented for v > 17. For several values of v, existence has been shown by constructing a TWh(v) with a prescribed, usually cyclic, automorphism group. In this article, it is shown that the strategy of constructing a TWh(v) with a prescribed automorphism group cannot succeed with TWh(17), since no 17‐player triplewhist tournament has nontrivial automorphisms. © 2004 Wiley Periodicals, Inc.
Racial discrimination in the Brazilian labour market: wage, employment and segregation effects
Authors: Arcand Jean‐Louis , D'hombres Béatrice
Published: November 2004

The social science literature has done much to document pervasive racial discrimination in Brazil and there is little doubt that a very dark colour is a handicap to social advancement. Nevertheless, very few empirical economic studies have attempted to quantify the impact of ethnic discrimination in Brazil. Using data culled from the Pesquisa National por Amostra de Domicílios (PNAD), this paper fills this void by analysing ethnic wage and employment gaps, as well as occupational segregation in Brazil, using the Oaxaca decomposition methodology. Copyright © 2004 John Wiley & Sons, Ltd.
Studies on bambara groundnut flour performance in Okpa preparation
Authors: Barimalaa Iminabo S , Agoha Gloria , Oboh Christian A , Kiin‐Kabari David B
Published: November 2004

Bambara groundnut flours of different particle sizes were prepared after bean seeds had been cold‐soaked and/or germinated, dried, milled and sieved. The flours were used to prepare okpa (local dish prepared by steaming mashed bambara groundnut) and their sensory properties determined. Viscosity of the flour pastes, before steaming, were also determined. Results showed that bambara groundnut flours from both germinated and cold‐soaked beans could be used in preparing good quality okpa and, therefore, remove all the problems involved in preparing the raw beans for okpa‐making as is done traditionally. Particle size appeared to play a major role in obtaining good okpa; therefore flours intended for okpa preparation should be such that 66, 86 and 96%, respectively, of cold‐soaked bean flour or 58, 78 and 91%, respectively, of germinated bean flour, after 1, 3 and 5 milling passes, should be in the particle range 1.5–4.5 × 10−4 m. Slightly higher amounts of the coarse (6.0 × 10−4 m) particles are needed in the germinated bean flours to compensate for the breakdown of starch and proteins, the gelling agents in bambara groundnut. Copyright © 2004 Society of Chemical Industry
Striking intrafamilial phenotypic variability and spastic paraplegia in the presence of similar homozygous expansions of the FRDA1 gene
Authors: Badhwar AmanPreet , Jansen An , Andermann Frederick , Pandolfo Massimo , Andermann Eva
Published: November 2004

We report on a Friedreich's ataxia (FA) family with 3 affected siblings with markedly different phenotypic presentations, including one with spastic paraplegia. Molecular analysis showed midsize GAA repeat expansion sizes in all 3 individuals. Gait spasticity in FA, although rare, has been described in a few patients who are compound heterozygotes for a point mutation, or who had GAA expansions of less than 200 repeats. The occurrence of spastic paraplegia in our family, in the presence of homozygous midsize GAA repeat expansions, is an unusual finding. Spasticity can be the main feature in both sporadic and familial patients with FA, either as an isolated finding, or in addition to other neurological abnormalities, and should be included as a rare feature in the clinical spectrum of FA. This family also demonstrates that in FA, marked intrafamilial phenotypic variability can arise in the presence of similar GAA expansion sizes. Therefore, in familial FA, the disease course in relatives therefore cannot be predicted solely from repeat length. Factors such as somatic mosaicism, repeat interruptions, modifying mutations and environmental factors must also be considered. © 2004 Movement Disorder Society
Identification of a hyaluronic acid (HA) binding domain in the PH‐20 protein that may function in cell signaling
Authors: Vines C.A. , Li M.W. , Deng X. , Yudin A.I. , Cherr G.N. , Overstreet J.W.
Published: November 2004

The macaque sperm surface protein PH‐20 is a hyaluronidase, but it also interacts with hyaluronic acid (HA) to increase internal calcium ( [Ca2+]i ) in the sperm cell. A region of the PH‐20 molecule, termed Peptide 2 (aa 205–235), has amino acid charge homology with other HA binding proteins. The Peptide 2 sequence was synthesized and two recombinant PH‐20 proteins were developed, one containing the Peptide 2 region (G3, aa 143–510) and one without it (E12, aa 291–510). On Western blots, affinity‐purified anti‐Peptide 2 IgG recognized the 64 kDa band corresponding to PH‐20 in acrosome intact sperm and, under reducing conditions, recognized the whole 67 kDa PH‐20 and the endoproteolyzed N‐terminal fragment of PH‐20. HA conjugated to a photoaffinity substrate specifically bound to sperm surface PH‐20. Indirect immunofluorescence demonstrated that Fab fragments of anti‐Peptide 2 IgG bound to the head of live sperm. Biotinylated HA was bound by Peptide 2 and by sperm extracts in a microplate binding assay, and this binding was inhibited by Fab fragments of anti‐Peptide 2 IgG. Biotinylated HA bound to the G3 protein and this binding was inhibited by anti‐Peptide 2 Fab, but HA did not bind to the E12 protein. Fab fragments of anti‐Peptide 2 IgG inhibited the increase in [Ca2+]i induced in macaque sperm by HA. Our results suggest that the Peptide 2 region of PH‐20 is involved in binding HA, which results in the cell signaling events related to the elevation of [Ca2+]i during sperm penetration of the cumulus. Mol. Reprod. Dev. 60: 542–552, 2001. © 2001 Wiley‐Liss, Inc.
DSC‐Ritz method for the free vibration analysis of Mindlin plates
Authors: Hou Yunshan , Wei G. W. , Xiang Y.
Published: November 2004

This paper introduces a novel method for the free vibration analysis of Mindlin plates. The proposed method takes the advantage of both the local bases of the discrete singular convolution (DSC) algorithm and the pb‐2 Ritz boundary functions to arrive at a new approach, called DSC‐Ritz method. Two basis functions are constructed by using DSC delta sequence kernels of the positive type. The energy functional of the Mindlin plate is represented by the newly constructed basis functions and is minimized under the Ritz variational principle. Extensive numerical experiments are considered by different combinations of boundary conditions of Mindlin plates of rectangular and triangular shapes. The performance of the proposed method is carefully validated by convergence analysis. The frequency parameters agree very well with those in the literature. Numerical experiments indicate that the proposed DSC‐Ritz method is a very promising new method for vibration analysis of Mindlin plates. Copyright © 2004 John Wiley & Sons, Ltd.
Risk factors for cholelithiasis in pregnancy
Authors: Lindseth Glenda , Bird‐Baker Marilyn Yellow
Published: November 2004

This study was designed to examine the relationships of demographics, anthropometrics, prenatal physical activity, serum cholesterol, and nutrient intakes to symptomatic cholelithiasis (gallstone) occurrence in 128 northern plains pregnant women. Data collected at 14 and 26 weeks of pregnancy and 4 weeks after delivery, indicated 25.8% of the Native American and 8.3% of the Caucasian pregnant women experienced symptoms of cholelithiasis. Body mass indices (BMIs) were significantly higher in the pregnant women who experienced cholelithiasis than in those who did not have cholelithiasis, and prenatal physical activity was significantly lower in those same women. History of gallbladder disease (β = .73; p = .001), BMI (β = .33; p = .01), and prenatal physical activity (β = −.20; p = .04) were predictive of increased occurrence of cholelithiasis during pregnancy. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:382–391, 2004
Intrauterine growth retardation in full‐term newborn infants with birth weights greater than 2,500 g
Authors: Steward Deborah K. , Moser Debra K.
Published: November 2004

Intrauterine growth retardation (IUGR) is an overlooked problem in full‐term infants with birth weights greater than 2,500 g. Birth weight less than the 10th percentile underestimates the presence of IUGR. The purpose of this study was to determine the prevalence of IUGR in full‐term infants and to identify sociodemographic and maternal characteristics associated with IUGR. The Ohio Department of Health Vital Statistics database was used to obtain data related to sociodemographic and maternal characteristics. The fetal growth ratio (FGR) was used to determine the presence of IUGR. The sample consisted of 1,569 infants with normal ratios and 1,364 infants classified as IUGR. Infants with IUGR were more often male and African American or Asian American. Maternal characteristics associated with IUGR included history of smoking during pregnancy, lower pre‐pregnancy weight, lower weight gain during pregnancy, and inadequate prenatal care. IUGR is present in a significant number of full‐term infants with birth weights greater than 2,500 g. The long‐term effects of IUGR in these infants remain to be determined. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:403–412, 2004
The reliability and validity of the Chinese version of the trait anxiety scale for children
Authors: Li Ho Cheung William , Lopez Violeta
Published: November 2004

The availability of a valid and reliable tool that accurately measures and differentiates pre‐operative anxiety level of children is crucial before any intervention can be appropriately planned, provided, and evaluated. The purposes of this study were to translate the original Trait Anxiety Scale for Children into Chinese and evaluate the psychometric properties of the newly translated scale for its utility in clinical practice and research. Five hundred and nineteen children from a primary school were recruited for this study. The instrument demonstrated adequate internal consistency reliability, and strong evidence of content and construct validity. Factor analysis confirmed the construct validity of the scale with a good fit between the factor structure of the scale and the observed data. Results suggest that the Chinese version of the Trait Anxiety Scale for Children can be used as a self‐report assessment tool in measuring trait anxiety level of Chinese children ages 7–12 years. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:426–434, 2004
Thermosensitive noncovalently bonded block copolymerlike micelles from interpolymer complexes
Authors: Topouza Dimitra , Orfanou Katerina , Pispas Stergios
Published: November 2004

Interpolymer complexes between polystyrene‐b‐poly(2‐vinylpyridine), (PS‐P2VP), and poly(methacrylic acid) (PMAA), have been studied in dioxane. Dioxane is a good solvent for PS‐P2VP copolymers but it is a nonsolvent for PMAA at room temperature. In this way noncovalent bonded micelles are formed after mixing the solutions of the polymers at 60 °C and then allowing them to cool at room temperature. Static and dynamic light scattering as well as viscosity measurements have been used to study the dependence of aggregate mass and size as a function of the molar ratio of functional groups in PS‐P2VP/PMAA mixtures, as well as temperature. Plots of apparent average molecular weight and hydrodynamic radius of the aggregates versus amine to carboxyl group ratio show a maximum at a ratio close to one. The size of the aggregates decreases at higher ratios because of the formation of more stable micelles with smaller cores. In all cases rather compact structures were formed, as evidenced by viscometry. The mass of the aggregates was found to decrease by an increase in temperature while hydrodynamic radii were increased. This was attributed to the increase of the thermodynamic quality of the solvent toward PMAA as temperature increases. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6230–6237, 2004
Counterion binding in Na poly(acrylate) gel. An 23Na‐NMR study
Authors: Minato Takafumi , Satoh Mitsuru
Published: November 2004

Counterion binding in Na poly(acrylate) gel immersed in water/organic solvent [ethanol (EtOH), acetonitrile (AcN), or tetrahydrofuran (THF)] mixtures was investigated by 23Na‐NMR spectroscopy. With an increase in the content of an organic solvent (∼40–50 vol %), the 23Na chemical shift significantly moved downfield on a gel collapse. This downfield shift strongly suggests that the gel collapse was induced by contact ion‐pair formation between the counterion and the carboxyl anion on the polymer. With a further increase in the solvent content (∼90 vol %), the chemical shift for an EtOH system showed a slight upfield shift, while THF and AcN systems maintained downfield shifts. The contrasting behaviors for EtOH and the latter two solvent systems were interpreted as being caused by desolvation and resolvation of bound Na+ counterions because of deswelling and reswelling of the respective gels in the pertinent solvent concentration regions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4412–4420, 2004
Electron–phonon coupling effects explored by inelastic neutron scattering
Authors: Pintschovius L.
Published: November 2004

This article gives a summary of inelastic neutron scattering studies searching for signatures of a strong electron–phonon coupling in high temperature superconductors. Special emphasis is laid on the anomalous dispersion, the unusually large linewidths and the anomalous temperature dependence observed for plane polarized copper‐oxygen bond‐stretching vibrations. It will be discussed in how far these results can be understood within conventional density functional theory or require recourse to theories for strongly correlated electrons, in particular the concept of charge stripe order. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prediction of repeated parasuicide after 1–12 months
Authors: Cedereke M. , Öjehagen A.
Published: November 2004

Background

To investigate predictors for repetition of suicide attempts 1–12 months after a suicide attempt.

Methods

Two hundred and sixteen patients who had made a suicide attempt were investigated after 1 month, and 178 were followed up again after 12 months.

Results

During 1–12 months after the suicide attempt, 30 patients reattempted suicide (repeaters). During 0–1 month 13 patients had reattempted suicide (early repeaters), and nine of them also repeated between 1 and 12 months. Repeaters had more often made three or more attempts before index attempt, they more often were in treatment at the index attempt and at 1 month they had lower global functioning and higher suicide ideation. In a Cox Regression analysis two predictors for repetition between 1 and 12 months remained significant; early repetition (OR 6.7, 95% CI, 3.0–14.9) and having GAF-scores below 49 (median cut-off) (OR 3.4 (95% CI, 1.5–7.5).

Conclusions

Our findings suggest that repetitive behaviour in itself is a strong predictor of future attempts. Strategies focusing on the repetitive behaviour are warranted.
The Bacillus subtilis DnaD protein: a putative link between DNA remodeling and initiation of DNA replication
Authors: Turner Ian J. , Scott David J. , Allen Stephanie , Roberts Clive J. , Soultanas Panos
Published: November 2004

The Bacillus subtilis DnaD protein is an essential protein and a component of the oriC and PriA primosomal cascades, which are responsible for loading the main replicative ring helicase DnaC onto DNA. We present evidence that DnaD also has a global DNA architectural activity, assembling into large nucleoprotein complexes on a plasmid and counteracting plasmid compaction in a manner analogous to that recently seen for the histone‐like Escherichia coli HU proteins. This DNA‐remodeling role may be an essential function for initiation of DNA replication in the Gram +ve B. subtilis, thus highlighting DnaD as the link between bacterial nucleoid reorganization and initiation of DNA replication.
United Nations High Commissioner for Refugees and status determination Imtaxaan in Kenya: an empirical survey
Authors: Odhiambo-Abuya E.
Published: November 2004

This article reports the results of a survey that the author conducted on procedures used by the United Nations High Commissioner for Refugees (“UNHCR”) to assess applications for asylum in Kenya. It focuses on some core challenges facing the regime. The article is divided into six sections. In the first, the procedures for seeking asylum are outlined. The second and third sections discuss issues relating to the financial situation of the UNHCR and, hence, its ability to process claims. The next section evaluates the contents of the letter that communicates an asylum decision and the extent to which it facilitates appeals. Questions regarding the removal of rejected claimants are examined in the penultimate section. In conclusion, the final section recommends that Kenya's refugee determination scheme needs to aim at realizing the standards set by UNHCR and international refugee and human rights laws. It also suggests that more efforts should be made at addressing the factors which produce refugees.
Association between Chlamydia trachomatis antibodies and subfertility in the Northern Finland Birth Cohort 1966 (NFBC 1966), at the age of 31 years
Authors: KARINEN L. , POUTA A. , HARTIKAINEN A.-L. , BLOIGU A. , PALDANIUS M. , LEINONEN M. , SAIKKU P. , JÄRVELIN M.-R.
Published: November 2004

The objective of this study was to assess the serological association between previous Chlamydia trachomatis infection and subfertility in a general population sample. A nested case (n=493)-control (n=986) study in a population-based birth cohort consisting of 12058 live births from the year 1966 was conducted. The analysis was restricted to those 6007 cohort members who replied to a postal inquiry and participated in a health examination including blood samples at the age of 31 years. The presence of C. trachomatis-specific serum IgG antibodies was screened by a synthetic peptide-based enzyme-linked immunosorbent assay. All the positive sera were further tested by the microimmunofluorescence method using immunotype pools and individual immunotypes of C. trachomatis as antigens. An association was found between the detection of immunotype-specific C. trachomatis antibodies and subfertility both in men and women. The results of the present study confirm the serological association between past C. trachomatis infections and subfertility in male or female partners of the couple in the population-based sample.
Seroprevalence of IgG against conformational and linear capsid antigens of parvovirus B19 in Italian blood donors
Authors: MANARESI E. , GALLINELLA G. , MORSELLI LABATE A. M. , ZUCCHELLI P. , ZACCARELLI D. , AMBRETTI S. , DELBARBA S. , ZERBINI M. , MUSIANI M.
Published: November 2004

Serum samples from 446 Italian blood donors between 18 and 65 years of age were analysed for the presence of IgG against parvovirus B19 capsid proteins VP1 and VP2 including conformational and linear epitopes. The overall prevalence of IgG against parvovirus B19 capsid proteins VP1 and VP2 against at least one antigen type was 79·1%. No significant difference was found between men and women. In the 18–27 years age group, 77·0% of the population had experienced infection with the virus, reaching 88·5% in the 48–57 years age group. The overall prevalence of IgG was 78·0% against conformational VP1+VP2 antigens, 74·9% against conformational VP2, 70·9% against linear VP1 and 23·3% against linear VP2 in the analysis of the IgG response against different conformational and linear epitopes of VP1 and VP2. Although IgG against conformational VP1+VP2, conformational VP2 and linear VP1 was present in more than 60% of subjects in all age groups, IgG against VP2 linear antigens was present in only 32% of subjects in the 18–27 years age group and then decreased to 20·5% in the 28–37 years age group. A different trend was noted when IgG positivity against linear and conformational epitopes was analysed separately in men and women. A significant increase was found in seroprevalence of IgG against VP2 conformational antigens with increasing age in males and a significant decrease in seroprevalence of IgG against VP2 linear antigens in women with increasing age.
Modelling transmission, immunity and disease of Haemophilus influenzae type b in a structured population
Authors: AURANEN K. , EICHNER M. , LEINO T. , TAKALA A. K. , MÄKELÄ P. H. , TAKALA T.
Published: November 2004

An individual-based stochastic simulation model was constructed to study the epidemiology of Haemophilus influenzae type b (Hib) transmission, immunity and invasive disease. Embedded in a demographic model, the transmission model of Hib carriage employs the most important social mixing patterns with three types of contact sites (family, day-care group, and school class). The model includes immunity against invasive Hib disease, initiated and boosted by Hib carriage and cross-reactive bacterial encounters. The model reproduces the observed age patterns in Hib carriage and disease in Finland before large-scale use of the Hib conjugate vaccines. The model was used to investigate characteristics of Hib transmission. The analysis emphasizes transmission between children and adults in families while pointing out the importance of pre-school and school-aged children in maintaining Hib circulation. Carriage in these age groups is thus identified as being essential to target for sustained effects of interventions by vaccination.
The epidemiology of the outbreak of severe acute respiratory syndrome (SARS) in Hong Kong – what we do know and what we don't
Authors: YU I. T. S. , SUNG J. J. Y.
Published: November 2004

Severe acute respiratory syndrome (SARS) struck Hong Kong bitterly in the spring of 2003, infecting 1755 persons and claiming nearly 300 lives. The epidemic was introduced by travellers from southern China, where the disease had originated. It started in late February and lasted until early June. Two notable ‘super-spreading’ events were reported, one inside a teaching hospital and the other in a private housing estate. Other than in the super-spreading events, the infectivity in the community appeared to be low, and there were few, if any, asymptomatic or subclinical infections. Health-care workers were at particular risk and accounted for 22% of all probable cases. The main modes of transmission were through droplet spread and close/direct contacts, but situations conducive to aerosol generation appeared to be associated with higher risk. Our review suggests that there are still many unknown factors concerning the mode of transmission and environmental risk that need to be clarified.
Female post‐reproductive lifespan: a general mammalian trait
Authors: Cohen Alan A.
Published: November 2004

Traditional explanations for the evolution of menopause and post‐reproductive lifespan in human females have been based on the benefits of maternal or grand‐maternal care outweighing the cost of lost reproduction. These explanations assume an evolutionary origin of menopause since human divergence with the most recent common ancestor. In this study, I conduct a literature survey of studies of 42 mammal species from eight orders, showing that post‐reproductive lifespan appears to be widespread among mammals. I then propose an alternative to traditional hypotheses: following accepted theories of trade‐offs and senescence, I suggest that the cost of extending reproductive lifespan might be relatively high in female mammals. Somatic and reproductive senescence appear to follow separate trajectories, so it is not surprising that the two processes should occur on different schedules. The timing of each process is probably determined by maximization of reproductive performance and survival early in adulthood, with consequent trajectories resulting in a post‐reproductive lifespan. The early end of reproduction relative to lifespan may be due to the cost of production and/or maintenance of oocytes, which decline exponentially over time. Oocyte number below a threshold may trigger an end to normal hormonal cycling.
The impact of location‐dependent correlation scales in ocean data assimilation
Authors: Zhou Guangqing , Fu Weiwei , Zhu Jiang , Wang Huijun
Published: November 2004

An approach is proposed to estimate the location‐dependent correlation scales for background error covariance matrix used in the 3D‐Var data assimilation, and the impact on ocean assimilation is examined. By a nonlinear fitting procedure, the horizontal scales are computed at each model grid point using the outputs of a tropical Pacific OGCM. The derived correlation scales are comparable to those obtained from observations, but present more complicated structures quite different from empirical functions. They vary largely in the horizontal and show a distinct distribution from surface to subsurface. Three assimilation experiments from 1982 to 2000 are performed to assess the improvement due to the location‐dependent correlation scales. The overall root‐mean‐square errors in the upper ocean are reduced about 0.5°C in the eastern equatorial Pacific and about 0.4°C in the western equatorial Pacific. The improvement shows the location‐dependent correlation scales can afford more information of the background error structures.
The effect of vertical measurement resolution on the correlation structure of a ground penetrating radar reflection image
Authors: Knight Rosemary , Tercier Paulette , Irving James
Published: November 2004

Geostatistical analysis of a ground penetrating radar reflection image can be used to quantify the maximum correlation direction and the range of horizontal and sub‐horizontal radar reflections. A review of previous work, and an analysis of a photograph of layered sediments, suggest that the vertical resolution of a radar image strongly affects its lateral correlation structure. Numerical modeling was used to generate synthetic radar sections and investigate the effect of the vertical resolution of the radar measurement on the link between the correlation structure of the radar reflections and the true correlation structure of subsurface water content. The horizontal range of the radar reflections decreased as the vertical resolution improved, closely matching that of the water content when the vertical resolution was approximately equal to the vertical range of the water content.
Internal structure of the Martian south polar layered deposits
Authors: Byrne S. , Ivanov A. B.
Published: November 2004

We investigate the three‐dimensional (3‐D) stratigraphic structure of the south polar layered deposits (SPLD) on Mars. Prominent bench‐forming layers exposed on SPLD scarps were observed and mapped in three dimensions using high‐resolution topographic and imaging data sets. Using the 3‐D location of exposures of one of these strata, we can accurately describe the shape of that layer using simple mathematical functions. Analysis of these functions and the surface topography can be used to reliably predict where on other scarps this layer is exposed. In general this bench‐forming layer (and its surrounding strata) is not flat and is well approximated as a parabolic dome near the center of the SPLD. Its curvature indicates that when deposited it was draped over a topographic dome similar in size to that of the present day. The scarps in which this layer is exposed must have formed subsequently and have not been significantly modified by flow processes. The basement topography exercises some control over the shape of the interior strata in extreme cases. Our successful layer‐fitting technique illustrates the regional uniformity in layer formation and the lack of major internal defects (such as faulting) within the SPLD. We have mapped exposures of what appear to be this layer in scarps farther from the center of the deposits. The position of these exposures can be used to modify the modeled parabolic shape at the periphery of the SPLD. These peripheral elevations provide constraints on the role of flow in the overall shaping of the SPLD.
Plasma shape and finite β effects on stability thresholds of the ion temperature gradient modes
Authors: Jhowry B. , Andersson J. , Dastgeer S.
Published: November 2004

The stability of electromagnetic ion temperature gradient driven modes with emphasis on the lower and upper stability thresholds is investigated by a collisionless magnetized plasma in both circular and noncircular geometry. The stability properties are discussed and the results are compared for finite β effects, arbitrary elongation, and Shafranov shift rate parameters. It has been found that the lower stability thresholds are weakly dependent on the (combined) effects of Shafranov shift rate, finite β, and elongation whereas the second (upper) stability regime shows substantial dependence depending on parameter regimes.
Covariant kinetic dispersion theory of linear waves in anisotropic plasmas. I. General dispersion relations, bi-Maxwellian distributions and nonrelativistic limits
Authors: Schlickeiser R.
Published: November 2004

The properties of longitudinal and transverse oscillations in unmagnetized anisotropic plasmas of arbitrary composition are investigated on the basis of Maxwell equations and the relativistic Vlasov equation. The longitudinal and transverse dispersion relations for plasmas with arbitrary distribution functions are derived. These dispersion relations describe the linear response of the system to the initial perturbations and thus define all existing linear plasma modes in the system. By analytic continuation the dispersion relations in the whole complex frequency plane are constructed. The further analysis is restricted to the important case of anisotropic bi-Maxwellian equilibrium plasma distribution functions. Explicit forms of the relativistically correct longitudinal and transverse dispersion relations are derived that hold for any values of the plasma temperatures and the temperature anisotropy. In the limit of nonrelativistic plasma temperatures the longitudinal and transverse dispersion relations can be expressed in terms of the Fried and Conte plasma dispersion function, however, the dependence on frequency and wave numbers is markedly different from the standard noncovariant nonrelativistic analysis. Only in the strictly unphysical formal limit of an infinitely large speed of light c→∞ the nonrelativistic dispersion relations reduce to the standard noncovariant nonrelativistic dispersion relations.
Particle acceleration during the coalescence of two magnetic loops in electron-ion plasmas
Authors: Saito Shinji , Sakai Jun-ichi
Published: November 2004

Electron and ion acceleration mechanisms during the coalescence process of two adjacent magnetic loops through cohelicity and counterhelicity magnetic reconnection are investigated by using a two-dimensional, electromagnetic, and relativistic particle-in-cell (PIC) simulation. Three types of acceleration mechanisms are found by the PIC simulations. (1) Electrons in a current sheet generated between two adjacent magnetic loops are accelerated by the electric field induced during the collisionless magnetic reconnection, and their energy spectrum is characterized by the power law. (2) Ions trapped in the front of fast magnetosonic shock waves generated during the coalescence process are promptly accelerated by the surfatron acceleration mechanism. (3) During the coalescence process through counterhelicity magnetic reconnection, ions outside the current sheet are accelerated by E×B drift, where the electrostatic fields E perpendicular to local magnetic field are generated by the collision between surrounding magnetic field barrier and electron-dominated jet from the current sheet. During the coalescence process through cohelicity magnetic reconnection, the electron energy spectrum in the current sheet is characterized by the power law whose index is about 5, while during the coalescence process through counterhelicity magnetic reconnection, the electron energy spectrum is characterized by the double power law whose indices are about 3.3 and 6. The simulation results obtained here are applied to the proton and electron acceleration during solar flares. The maximum energy of accelerated electrons reaches about 100 keV, while the maximum energy of accelerated protons by the surfatron acceleration mechanism is about 10 MeV for both cohelicity and counterhelicity case.
Global structure of zonal flow and electromagnetic ion temperature gradient driven turbulence in tokamak plasmas
Authors: Miyato Naoaki , Kishimoto Yasuaki , Li Jiquan
Published: November 2004

Global characteristics of the coupled system of zonal flows and electromagnetic ion temperature gradient driven turbulence in tokamak plasmas are investigated using a global electromagnetic Landau fluid code. Zonal flow behavior changes with the safety factor q. In a low q region stationary zonal flows are excited and they suppress the turbulence effectively. Coupling between zonal flows and poloidally asymmetric pressure perturbations due to a geodesic curvature makes the zonal flows oscillatory in a high q region. Energy transfer from the oscillatory zonal flows to the turbulence via the poloidally asymmetric pressure perturbations is identified. Therefore in the high q region where the zonal flows are oscillatory, the zonal flows cannot quench the turbulence and turbulent transport is not suppressed completely. As for the zonal flow behavior, it is favorable for confinement improvement to make the low q region where the stationary zonal flows are dominant in tokamak plasmas.
On final states of two-dimensional decaying turbulence
Authors: Yin Z.
Published: November 2004

Numerical and analytical studies of final states of two-dimensional (2D) decaying turbulence are carried out. The first part of this work is trying to give a definition for final states of 2D decaying turbulence. The functional relation of ω-ψ, which is frequently adopted as the characterization of those final states, is merely a sufficient but not necessary condition; moreover, it is not proper to use it as the definition. It is found that the method through the value of the effective area S covered by the scatter ω-ψ plot, initially suggested by Read, Rhines, and White [“Geostrophic scatter diagrams and potential vorticity dynamics,” J. Atmos. Sci. 43, 3226 (1986)] is more general and suitable for the definition. Based on this concept, a definition is presented, which covers all existing results in late states of decaying 2D flows (including some previous unexplainable weird double-valued ω-ψ scatter plots). The remaining part of the paper is trying to further study 2D decaying turbulence with the assistance of this definition. Some numerical results, leading to “bar” final states and further verifying the predictive ability of statistical mechanics [Yin, Montgomery, and Clercx, “Alternative statistical-mechanical descriptions of decaying two-dimensional turbulence in terms of patches and points,” Phys. Fluids 15, 1937 (2003)], are reported. It is realized that some simulations with narrow-band energy spectral initial conditions result in some final states that cannot be very well interpreted by the statistical theory (meanwhile, those final states are still in the scope of the definition).
Magnetization measurements on Li2Pd3B superconductor
Authors: Badica P. , Kondo T. , Kudo T. , Nakamori Y. , Orimo S. , Togano K.
Published: November 2004

Magnetization in dc magnetic fields and at different temperatures has been measured on the antiperovskite Li2Pd3B with a cubic structure composed of distorted Pd6B octahedrons. This material was recently found to exhibit superconductivity at 7–8K. The critical fields Hc1(0) and Hc2(0) are determined to be 135Oe and 4T, respectively. Critical current density, scaling of the pinning force within the Kramer model, and irreversibility field data are presented. Several superconductivity parameters were deduced: Coherence length ξ=9.1nm, penetration depth λ=194nm, and Ginzburg–Landau parameter κ=21. The material resembles other boride superconductors from the investigated points of view.
Anomalous current–voltage characteristics and colossal electroresistance of amorphous carbon film on Si substrate
Authors: Xue Q. Z. , Zhang X. , Tian P. , Jin C.
Published: November 2004

Amorphous carbon film (a-C film) was deposited on n-Si substrate by pulsed-laser deposition at room temperature. The electrical transport properties of a-C film/n-Si were investigated by current–voltage (I–V) measurements at various temperatures. The results indicate that the resistance of a-C film/n-Si is controlled by the applied electric current. The most important result is that when the value of the electric voltage is larger than a threshold, the current increases abruptly to a very large value, and the value of the voltage threshold decreases with increasing temperature. Correspondingly, the colossal electroresistance (ER) was achieved in the temperature range measured. The ER reaches −84.5% and −99.5% at T=310K and 170K, respectively. The mechanism of the I–V characteristics may be understood by an energy band structure of a-C film/n-Si. The anomalous I–V characteristics and colossal ER should be of interest for various applications such as field-effect devices.