bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolated paraaortic lymph‐node recurrence after the curative resection of colorectal carcinoma
Authors: Min Byung Soh , Kim Nam Kyu , Sohn Seung Kook , Cho Chang Hwan , Lee Kang Young , Baik Seung Hyuk
Published: October 2007

Background and objectives

Isolated paraaortic lymph‐node recurrence (IPLR) after curative surgery for colorectal carcinoma is rare and no previous report has specifically addressed this type of recurrence. We investigated the clinical features of IPLR and analyzed prognostic factors.

Methods

Of 2,916 patients who underwent curative surgery for colorectal carcinoma, IPLR was identified in 38 patients (1.3%). The clinical features and prognostic factors of these patients were analyzed.

Results

IPLR was first detected by increased serum carcinoembryonic antigen (CEA) levels (63.2%) or by routine follow‐up computed tomography (CT) (36.8%). Curative resection of IPLR was performed in six patients (15.8%). A total of 19 patients (50.0%) received chemoradiation therapy and 13 patients (34.2%) received chemotherapy only. The median survival from IPLR was 13 months (range: 5–60 months). The median survival time from IPLR for the resected patients was 34 months, whereas it was 12 months for those who did not undergo resection (P = 0.034). The factors associated with the prognosis were histological grade (P = 0.003), location (P = 0.032), and resection of IPLR (P = 0.034).

Conclusions

IPLR after curative surgery for colorectal carcinoma is rare. Although it is generally associated with poor prognosis, better survival might be achieved through curative resection in selected cases. J. Surg. Oncol. 2008;97:136–140. © 2007 Wiley‐Liss, Inc.
Performance of R‐N(R′)‐R′′ functionalised poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) monolithic sorbent for plasmid DNA adsorption
Authors: Danquah Michael K. , Ho Jenny , Forde Gareth M.
Published: October 2007

High‐throughput plasmid DNA (pDNA) manufacture is obstructed predominantly by the performance of conventional stationary phases. For this reason, the search for new materials for fast chromatographic separation of pDNA is ongoing. A poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) (GMA‐EGDMA) monolithic material was synthesised via a thermal‐free radical reaction, functionalised with different amino groups from urea, 2‐chloro‐N,N‐diethylethylamine hydrochloride (DEAE‐Cl) and ammonia in order to investigate their plasmid adsorption capacities. Physical characterisation of the monolithic polymer showed a macroporous polymer having a unimodal pore size distribution pivoted at 600 nm. Chromatographic characterisation of the functionalised polymers using pUC19 plasmid isolated from E. coli DH5α‐pUC19 showed a maximum plasmid adsorption capacity of 18.73 mg pDNA/mL with a dissociation constant (KD) of 0.11 mg/mL for GMA‐EGDMA/DEAE‐Cl polymer. Studies on ligand leaching and degradation demonstrated the stability of GMA‐EGDMA/DEAE‐Cl after the functionalised polymers were contacted with 1.0 M NaOH, which is a model reagent for most ‘cleaning in place’ (CIP) systems. However, it is the economic advantage of an adsorbent material that makes it so attractive for commercial purification purposes. Economic evaluation of the performance of the functionalised polymers on the grounds of polymer cost (PC)/mg pDNA retained endorsed the suitability of GMA‐EGDMA/DEAE‐Cl polymer.
Visible light‐induced photopolymerization of an in situ macroporous sol–gel monolith
Authors: Dulay Maria T. , Choi Han Nim , Zare Richard N.
Published: October 2007

A one‐step, in situ, photopolymerization of a mixture of methacryloxypropyltrimethoxysilane in the presence of an acid catalyst, water, and toluene is accomplished in a 75 μm id polyimide‐coated capillary using visible light (460 nm) for a 15 min irradiation time. The mixture is a two‐component photosystem comprising Irgacure 784 photosensitizer and diphenyliodonium chloride photoinitiator. The visible photopolymerized sol–gel (vis‐PSG) column shows RP chromatographic behavior. The analytical potential of these columns is demonstrated with the isocratic separation of small, neutral alkyl phenyl ketones. Operational parameters, such as mobile phase composition, field strength, and column temperature were varied to assess how they affect the separation performance of the monolith.
Alkylated poly(styrene‐divinylbenzene) monolithic columns for μ‐HPLC and CEC separation of phenolic acids
Authors: Kučerová Zdenka , Szumski Michal , Buszewski Boguslaw , Jandera Pavel
Published: October 2007

Macroporous poly(styrene‐divinylbenzene) monolithic columns were prepared in fused silica capillaries of 100 μm id by in‐situ copolymerization of styrene with divinylbenzene in the presence of propan‐1‐ol and formamide as the porogen system. The monoliths were subsequently alkylated with linear alkyl C‐18 groups via Friedel‐Crafts reaction to improve the retention and chromatographic resolution of strongly polar phenolic acids. A new thermally initiated grafting procedure was developed in order to shorten the time of the alkylation process. The grafting procedure was optimized with respect to the reaction temperature, time, the grafting reactant concentration, and the solvent used. The type of solvent and the grafting temperature are the most significant factors affecting the hydrodynamic properties, porosity, and efficiency of the columns. While the equivalent particle diameter of the grafted column increased, the capillary‐like flow‐through pore diameter decreased in comparison to non‐alkylated monoliths. The hydrodynamic permeability of the monolith decreased, but the monolithic column still permitted fast μ‐HPLC separations.
Cyclopamine treatment of full‐blown Hh/Ptch‐associated RMS partially inhibits Hh/Ptch signaling, but not tumor growth
Authors: Ecke Ines , Rosenberger Albert , Obenauer Silvia , Dullin Christian , Aberger Fritz , Kimmina Sarah , Schweyer Stefan , Hahn Heidi
Published: October 2007

Mutations in the Hedgehog (Hh) receptor Patched (Ptch) are responsible for a variety of tumors, which show ligand‐independent stimulation of the Hh/Ptch signaling cascade. Cyclopamine is an alkaloid of the corn lily Veratrum californicum, which blocks activity of the pathway by inhibition of Smoothened (Smo), the signal transduction partner of Ptch. This results in growth inhibition of Hh/Ptch‐dependent tumor cells in vitro, of subcutaneous xenografts as well as of precancerous lesions in Ptch+/− mice. However, the evidence that treatment with cyclopamine is an effective anti‐cancer therapy against full‐blown tumors is sparse. Here, we have investigated the responsiveness of full‐blown Hh/Ptch‐associated rhabdomyosarcoma (RMS) to this drug. Hh pathway activity and proliferation of cultured primary RMS cells was inhibited by cyclopamine. Hh signaling was also partially suppressed by the drug in RMS in vivo, but cyclopamine treatment did not result in stable disease or tumor regression. It also did not affect proliferation, apoptosis or the differentiation status of RMS. This was in contrast to anti‐proliferative effects on tumor growth caused by doxorubicin, an anthracycline routinely used in therapy of human RMS. In summary, our data indicate that there must be additional factors that render full‐blown Hh/Ptch‐associated RMS insensitive against anti‐proliferative effects of cyclopamine in vivo. © 2007 Wiley‐Liss, Inc.
Antipsychotic polypharmacy at the University Psychiatric Hospital in Serbia
Authors: Divac Nevena , Jašović‐Gašić Miroslava , Samardžić Ranka , Lačković Maja , Prostran Milica
Published: October 2007

The aim of the study was to analyse the prevalence of polypharmacy with antipsychotic drugs and analyse types of coprescribing episodes at the University Psychiatric Hospital in Serbia.

A sample of 120 patients (198 hospitalisations) was analysed. The prevalence of polypharmacy was calculated as the proportion of patients receiving two or more antipsychotic drugs concomitantly for at least 28 days. Total daily antipsychotic drug load was calculated as the number of defined daily doses (DDDs) of drugs per patient per day. It was compared between patients receiving monotherapy and patients receiving polypharmacy. Statistics was performed using standard statistical methods.

Monotherapy was prescribed during 32.3% hospitalisations (n = 64), while polypharmacy was noted in 67.7% (n = 134). Polypharmacy with two drugs was observed during 126 (63.6%) hospitalisations and three antipsychotics were prescribed concomitantly during 8 (4.1%) hospitalisations. Patients' characteristics were not significantly different between patients who received only monotherapy and patients receiving polypharmacy. Patients on monotherapy had significantly more prior hospitalisations than patients from the other group (t = 3.94, df = 119, p < 0.001).

The prevalence of polypharmacy patient episodes (67.7%) is approximately 100% higher than the prevalence observed in developed European countries. The explanation of such prescribing habit of Serbian psychiatrists requires further investigation. The only distinguishing factor between patients receiving monotherapy and patients receiving polypharmacy is the number of prior hospitalisations. Copyright © 2007 John Wiley & Sons, Ltd.
Ein Lichtkarussell für kalte Atome
Authors: Franke‐Arnold Sonja
Published: October 2007

Seit längerem ist es möglich, Atome in Lichtgittern einzusperren. Unserer Gruppe an der Universität Glasgow ist es gelungen, ringförmige Lichtgitter zu erzeugen, die sich drehen. Ziel ist es, Bose‐Einstein Kondensate in diesen rotierenden Gittern einzufangen und zu untersuchen. Die Anzahl der Gitterplätze, die Rotationsgeschwindigkeit und die Potentialbarrieren zwischen den einzelnen Gitterplätzen lassen sich einfach variieren.
Bilder einer Brille als Hohlspiegel
Authors: Schlichting H. Joachim
Published: October 2007

Hält man eine Brille vor eine Leuchte, so kann man interessante optische Phänomene beobachten. Diese liefern Informationen über die Beschaffenheit der Brillengläser – und des Brillenträgers.
A Mg2+‐induced conformational switch rendering a competent DNA polymerase catalytic complex
Authors: Mendieta Jesús , Cases‐González Clara E. , Matamoros Tania , Ramírez Galo , Menéndez‐Arias Luis
Published: October 2007

The structural and dynamical changes occurring before nucleotide addition were studied using molecular dynamics (MD) simulations of human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase (RT) complexes containing one or two Mg2+ ions in the presence of dNTP. Our models revealed that the formation of a catalytically competent DNA polymerase complex required subtle rearrangements at the catalytic site A, which occurred only when an Mg2+ ion was bound. This model has been validated using pre‐steady‐state kinetics to show that free Mg2+ is necessary to obtain a catalytically competent polymerase. Kinetic studies carried out with Be2+ as a cofactor permitted the functional discrimination between metal sites A and B. At low concentrations, Be2+ increased the catalytic efficiency of the polymerase, while at higher concentrations, it competed with Mg2+ for binding to site A, and inhibited DNA polymerization. In agreement with experimental data, MD simulations revealed that the catalytic attack distance between the 3′‐OH of the primer and the α phosphorus in complexes containing Be2+ instead of Mg2+ at site A was above 4.5 Å. Our findings provide a detailed description of the mechanism of DNA polymerization and should be helpful to understand the molecular basis of DNA replication fidelity. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Daily stress and pain sensitivity in chronic tension‐type headache sufferers
Authors: Cathcart Stuart , Pritchard Donald
Published: October 2007

The aim was to examine interactions between daily stress, pain sensitivity, and headache activity in Chronic Tension‐Type Headache sufferers. We measured daily hassles, pericranial muscle tenderness, pressure pain threshold at finger, headache history (years of headache) and prospective headache activity (in a two‐week clinical diary), in headache sufferers and healthy Controls. Headache sufferers had increased daily hassles scores, increased muscle tenderness, and decreased pain threshold compared to Controls. Daily hassles were correlated with increased muscle tenderness and reduced pain threshold in the CTH group. In regression analyses, daily hassles predicted muscle tenderness when accounting for headache history, headache severity and pain threshold. Muscle tenderness and daily hassles predicted headache severity when accounting for headache history and pain threshold. Muscle tenderness predicted pain threshold when accounting for headache history, headache severity and daily hassles. The results indicate daily stress is related to increased pain sensitivity and headache activity in Chronic Tension‐Type Headache sufferers, accounting for significant variance in these factors additional to that accounted for by clinical factors (headache history and severity). Although only correlational, the results support the proposition that daily stress affects Chronic Tension‐Type Headache through hyperalgesic effects on already sensitized pain pathways in headache sufferers. Copyright © 2007 John Wiley & Sons, Ltd.
An extensible and lightweight architecture for adaptive server applications
Authors: Gorton Ian , Liu Yan , Trivedi Nihar
Published: October 2007

Server applications augmented with behavioral adaptation logic can react to environmental changes, creating self‐managing server applications with improved quality of service at runtime. However, developing adaptive server applications is challenging due to the complexity of the underlying server technologies and highly dynamic application environments. This paper presents an architecture framework, the Adaptive Server Framework (ASF), to facilitate the development of adaptive behavior for legacy server applications. ASF provides a clear separation between the implementation of adaptive behavior and the business logic of the server application. This means a server application can be extended with programmable adaptive features through the definition and implementation of control components defined in ASF. Furthermore, ASF is a lightweight architecture in that it incurs low CPU overhead and memory usage. We demonstrate the effectiveness of ASF through a case study, in which a server application dynamically determines the resolution and quality to scale an image based on the load of the server and network connection speed. The experimental evaluation demonstrates the performance gains possible by adaptive behavior and the low overhead introduced by ASF. Copyright © 2007 John Wiley & Sons, Ltd.
Surface and Biological Activity of Some Novel Cationic Surfactants
Authors: Badawi A. M. , Mekawi M. A. , Mohamed A. S. , Mohamed M. Z. , Khowdairy M. M.
Published: October 2007

In this study, steps were taken toward the development of bactericidal and fungicidal synthetic cationic surfactants by reacting decyl, dodecyl or tetradecyl amine with acetic or hydrochloric acid to produce a series of amine salts which consequently converted to copper or cobalt cationic complexes via complexing the first series compounds with copper (II) or cobalt (II) ions. Surface properties such as interfacial tension and emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration (CMC), maximum surface excess (Γmax) and minimum surface area (Amin) were studied. Free energy of micellization (ΔG°mic) and adsorption (ΔG°ads) were calculated. The antimicrobial activity was determined via the inhibition zone diameter of the prepared compounds, which measured against five strains of a representative group of microorganisms. FTIR spectra, elemental analysis and H1 NMR spectrum were performed to confirm compound structure and purity.
TGFβ intercepts nuclear glycogen synthase kinase 3β to inhibit PDGF‐induced DNA synthesis in mesangial cells
Authors: Das Falguni , Mahimainathan Lenin , Ghosh-Choudhury Nandini , Venkatesan Balachandar , Kasinath Balakuntalam S. , Abboud Hanna E. , Ghosh Choudhury Goutam
Published: October 2007

Here, we demonstrate a mechanism of TGFβ‐mediated inhibition of PDGF‐induced DNA synthesis in mesangial cells. TGFβ significantly inhibited nuclear Akt phosphorylation without any effect on PDGF‐stimulated phosphorylation of PDGFR at PI 3 kinase binding site (Tyr‐751). Remarkably, TGFβ inhibited cyclin D1 and cyclin E expression with concomitant decrease in CDK2 activity induced by PDGF. More importantly, we demonstrate that TGFβ significantly abolished Akt‐mediated serine‐9 phosphorylation of glycogen synthase kinase 3β (GSK3β), thus prevented its inactivation. Expression of inactive GSK3βK85R mutant increased cyclin D1 expression and DNA synthesis similar to PDGF. These results provide the first evidence that TGFβ intercepts Akt kinase activity in the nucleus to block inactivation of GSK3β, leading to attenuation of PDGF‐induced CDK2 activity and DNA synthesis.
Vascular endothelial cell senescence mediated by integrin β4 in vitro
Authors: Liu Xia , Yin Deling , Zhang Yun , Zhao Jing , Zhang Shangli , Miao Junying
Published: October 2007

To understand whether integrin β4 is involved in vascular endothelial cell (VEC) senescence, we examined integrin β4 level changes, as well as P53 and reactive oxygen species (ROS) levels and alterations of phosphatidylcholine‐specific phospholipase C (PC‐PLC) activity before and after knocking‐down integrin β4 by small interfering RNA. We found integrin β4, P53 and ROS levels increased significantly, while Ca2+‐independent PC‐PLC activity obviously decreased during VEC senescence. On the other hand, integrin β4 down‐regulation attenuated the senescence phenotype and reversed Ca2+‐independent PC‐PLC activity, and P53 and ROS levels. The data suggested that integrin β4 might mediate VEC senescence through depressing Ca2+‐independent PC‐PLC and elevating the levels of P53 and ROS.
Two Mms2 residues cooperatively interact with ubiquitin and are critical for Lys63 polyubiquitination in vitro and in vivo
Authors: Pastushok Landon , Spyracopoulos Leo , Xiao Wei
Published: October 2007

Recent structural analyses support a model whereby Mms2 interacts with and orientates Ub to promote Ubc13‐mediated Lys63 chain formation. However, residues of the hMms2–Ub interface have not been addressed. We found two hMms2 residues to be critical for binding and polyUb conjugation. Surprisingly, while each single mutation reduces the binding affinity, the double mutation causes significant reduction of Ub binding and abolishes polyUb chain formation. Furthermore, the corresponding yeast mms2 double mutant exhibited an additive phenotype that caused a complete loss of MMS2 function. Taken together, this study identifies key residues of the Mms2–Ub interface and provides direct experimental evidence that Mms2 physical association with Ub is correlated with its ability to promote Lys63‐linked Ub chain assembly.
Sonographic findings in women with complications after hysterectomy
Authors: Seffah J.D. , Adanu Richard M.K.
Published: October 2007

Objective

To study the role of abdominal ultrasound in the management of complications after emergency or elective hysterectomy.

Methodology

The study compared 102 women who had complications after emergency peripartum hysterectomy (study group) with 102 women who had complications after elective hysterectomy for fibroids (control group).

Results

The study group had a lower mean age (31.1 ± 2.1 vs 40.1 ± 3.4 years) but higher parity (3.0 ± 1.3 vs 2.0 ± 1.2) compared with the control group. The primary complication in the study group was abdominal mass or distension (55.9%) compared with chronic abdominal pain (49.0%) in the control group. The leading sonographic abnormality in the study group was pelvic abscess (9.8%) while hydrosalpinx (6.9%) was more common in the control group. There was no statistical difference in the findings between the groups. Management of complications included ovarian cystectomy and drainage of pelvic abscesses.

Conclusion

Ultrasound facilitates accurate diagnosis of complications after hysterectomy and enhances management.
Cervical priming with misoprostol prior to transcervical procedures
Authors: Fiala C. , Gemzell‐Danielsson K. , Tang O.S. , von Hertzen H.
Published: October 2007

Cervical priming with misoprostol has shown to facilitate transcervical procedures and to reduce side‐effects. Cervical priming is recommended by several evidence‐based guidelines prior to surgical abortion, dilatation and curettage, hysteroscopy and intrauterine device insertion. It is effective in pregnant as well as in non‐pregnant women while the results in post‐menopausal women are conflicting. Misoprostol is the best suited prostaglandin for a number of reasons: it has a short half‐life, few side effects, it is stable at room temperature, it is relatively cheap and the dosage can easily be adjusted according to the clinical need. Various doses, routes, and time intervals between misoprostol application and the intervention have been evaluated. A single dose of 400 μg given sublingually or vaginally 3h before the intervention has given the best efficacy with the least side effects. Higher doses or longer intervals do not improve the effect on the cervix. Pain is a frequent side effect, but usually responds well to NSAIDs. Other side effects are rare.
Misoprostol for intrauterine fetal death
Authors: Gómez Ponce de León R. , Wing D. , Fiala C.
Published: October 2007

The frequency of intrauterine fetal death (IUFD) with retained fetus varies, but is estimated to occur in 1% of all pregnancies. The vast majority of women will spontaneously labor and deliver within three weeks of the intrauterine death. The complexity in medical management increases significantly when the cervix is unripe or unfavorable, or when the woman develops disseminated intravascular coagulation. Misoprostol regimens for the induction of labor for second and third trimester IUFDs, range from 50 to 400 μg every 3 to 12 h, and are all clinically effective. Nevertheless, the current scientific evidence supports vaginal misoprostol dosages, which are adjusted to gestational age: between 13–17 weeks, 200 μg 6‐hourly; between 18–26 weeks, 100 μg 6‐hourly; and more than 27 weeks, 25–50 μg 4‐hourly. In women with a previous cesarean, lower doses should be used and doubling of doses should not occur. Clinical monitoring should continue after delivery or expulsion because of the risk of postpartum atony and/or placenta retention.
Cracks in the ‘Mightiest Fortress’: Jamaat-e-Islami's Changing Discourse on Women
Authors: AHMAD IRFAN
Published: October 2007

Islamists' ideas about the position of women are readily invoked to portray them as ‘anti-modern’. The operating assumption is that Islamism (mutatis mutandis Islam) sanctions gender hierarchy. In this paper, drawing on ethnographic research and written sources of the Jamaat-e-Islami of India, founded in 1941, I question such assumptions. While defending Islam against the ‘epidemic’ of westernization, Maududi (b. 1903), the Jamaat's founder, called women ‘the mightiest fortress of Islamic culture’. Invoking the Quran and Prophetic traditions, he argued that women should not step outside of the home, and must veil themselves from head to toe. He stood against any political role for women. For decades, Maududi's interpretation went uncontested. However, from the 1970s onwards many members of the Jamaat began to critique Maududi and offered an alternative reading of Islam. They argued that women could indeed leave the home, assume key economic and political roles, unveil their faces, as well as act in films. By highlighting such voices and analysing the sociological coordinates of the contestations within the Jamaat, I underscore the transformation in the Jamaat's discourse. I conclude by discussing whether the critiques of Maududi by his own followers inaugurate an alternative discourse of Islamic feminism.
Evaluation of an in vitro and in vivo model for experimental infection with Leishmania (Viannia) braziliensis and L. (V.) peruviana
Authors: GAMBOA D. , TORRES K. , DONCKER S. DE , ZIMIC M. , AREVALO J. , DUJARDIN J.-C.
Published: October 2007

Leishmania (Viannia) braziliensis and L. (V.) peruviana are two parasite species characterized by a very different pathogenicity in humans despite a high genetic similarity. We hypothesized previously that L. (V.) peruviana would descend from L. (V.) braziliensis and would have acquired its ‘peruviana’ character during the southward colonization and adaptation of the transmission cycle in the Peruvian Andes. In order to have a first appreciation of the differences in virulence between both species, we evaluated an in vitro and in vivo model for experimental infection. A procedure was adapted to enrich culture forms in infective stages and the purified metacyclics were used to infect macrophage cell lines and golden hamsters. The models were tested with 2 representative strains of L. (V.) braziliensis from cutaneous and mucosal origin respectively and 2 representative strains of L. (V.) peruviana from Northern and Southern Peru respectively. Our models were reproducible and sensitive enough to detect phenotypic differences among strains. We showed in vitro as well as in vivo that the L. (V.) braziliensis was more infective than L. (V.) peruviana. Furthermore, we found that in vitro infectivity patterns of the 4 strains analysed, were in agreement with the geographical structuring of parasite populations demonstrated in our previous studies. Further work is needed to confirm our results with more strains of different geographical origin and their specific clinical outcome. However, our data open new perspectives for understanding the process of speciation in Leishmania and its implications in terms of pathogenicity.
Political Prophecy in Contemporary American Literature: The Left-Conservative Vision of Norman Mailer
Authors: Zirakzadeh Cyrus Ernesto
Published: October 2007

Popular and prize-winning writer Norman Mailer has advanced a view of American politics and society that he calls “left conservatism.” This paper analyzes elements of Mailer's critique and describes how the parts fit together. Special attention is given to his interpretation of economic history and social psychology, his vision of moral health that he associates with the term “hipster,” and his fear of a new political mentality in the United States that he conveys through a neologism, the “wad.” The paper closes with a sketch of the ways Mailer's left conservatism both dovetails with and departs from the concerns and arguments of other contemporary American conservative thinkers.
Molecular typing ofCryptosporidium parvumassociated with a diarrhoea outbreak identifies two sources of exposure
Authors: MATTSSON J. G. , INSULANDER M. , LEBBAD M. , BJÖRKMAN C. , SVENUNGSSON B.
Published: October 2007

An outbreak of cryptosporidiosis associated with exposure to outdoor swimming-pool water affected an estimated 800–1000 individuals. PCR products were obtained from faecal specimens from 30 individuals who tested positive forCryptosporidiumoocysts. RFLP and sequencing analyses showed that all individuals were infected withCryptosporidium parvum. Among the infected individuals, five had just swum in an adjacent indoor pool during the same period, and had no identified contact with individuals linked to the outdoor pool. With the use of subgenotyping based on analysis of three mini- and microsatellite loci, MS1, TP14, and GP15, we could identify two sources of exposure. One subtype was associated with the outdoor pool and another with the indoor pool. These data demonstrate that the use of mini- and microsatellite loci as markers for molecular fingerprinting ofC. parvumisolates are valuable in the epidemiological investigation of outbreaks.
Trends in incidence of pneumococcal disease before introduction of conjugate vaccine: South West England, 1996–2005
Authors: IHEKWEAZU C. A. , DANCE D. A. B. , PEBODY R. , GEORGE R. C. , SMITH M. D. , WAIGHT P. , CHRISTENSEN H. , CARTWRIGHT K. A. V. , STUART J. M.
Published: October 2007

Introduction of pneumococcal conjugate and polysaccharide vaccines into the United Kingdom's routine immunization programmes is expected to change the epidemiology of invasive pneumococcal disease (IPD). We have documented the epidemiology of IPD in an English region (South West) with high-quality surveillance data before these programmes were established. We analysed data on isolates of Streptococcus pneumoniae from blood and CSF between 1996 and 2005 from microbiology laboratories in the South West that were reported and/or referred for serotyping to the Health Protection Agency Centre for Infections. The mean annual incidence of IPD increased from 11·2/100 000 in 1996 to 13·6/100 000 in 2005 (P<0·04). After adjusting for annual blood-culture sampling rates in hospitals serving the same catchment populations, an increase in annual incidence of IPD was no longer observed (P=1·0). Variation in overall incidence between laboratories could also be explained by variation in blood culture rates. The proportion of disease caused by serotypes 6B, 9V and 14 decreased significantly (P=0·001, P=0·007, and P=0·027 respectively) whereas that caused by serotype 4, 7F and 1 increased (P=0·001, P=0·003, and P<0·001 respectively) between 2000 and 2005. The level of penicillin non-susceptibility and resistance to erythromycin remained stable (2% and 12% respectively). This study provides an important baseline to assess the impact of changing vaccination programmes on the epidemiology of IPD, thus informing future use of pneumococcal vaccines.
New Zealand sub-Antarctic phytoliths and their potential for past vegetation reconstruction
Authors: Thorn Vanessa C.
Published: October 2007

Phytoliths in the modern vegetation of sub-Antarctic Campbell Island are compared with those in the soil beneath to assess the accuracy of vegetation reconstructions made from dispersed phytolith assemblages. The soil phytoliths alone suggest the source vegetation is a grassland association for all study sites, which reflects none of the herb, fern or shrub component of the overlying vegetation. It is concluded that at this locality dispersed phytoliths on their own are not reliable indicators of source vegetation and should be used with caution in this context for palaeoecological studies. However, they can provide useful botanical information where all other organic material is absent. With further research, based on the abundance and diversity of Poaceae phytoliths observed in this and other studies, dispersed phytoliths from the fossil record have the potential to contribute significantly to the understanding of grassland ecosystem development in the geological past.
Of tribes and territories
Authors: Graves-Brown Paul
Published: October 2007

Do good fences make good neighbours? According to their account, Duncan Garrow and Elizabeth Shove each inhabit ‘neighbouring territory’ (p. 127) and are undertaking an exercise in ‘intellectual tourism’ (p. 127). In the process, they find that they live in ‘substantially different worlds’ (p. 128). It is not for me to cast doubt on the veracity of their personal experience, but I do not think it is representative of the state of ‘interdisciplinary working’. Disciplines do inhabit different territories, some are quite distinct; physics and French probably share few boundaries. Others -- archaeology, sociology and anthropology – constantly rub up against each other. Boundedness can be emphatic where disciplines are more ‘urban’, clustered tightly around specific methodologies and data; others are more ‘rural’, with a diversity of topics, methods and theories which are likely to overlap with other disciplines (Becher 1989). Archaeology falls into the latter category; there are wide differences of approach between prehistory, classical archaeology, Egyptology, historical archaeology or archaeological science. My impression is that sociology would also fit the rural description.
A numerical model for coupled fluid flow and matrix deformation with applications to disequilibrium compaction and delta stability
Authors: Morency Christina , Huismans Ritske S. , Beaumont Christopher , Fullsack Philippe
Published: October 2007

A model is developed which couples fully saturated porous compaction to the viscous‐plastic deformation of the skeleton matrix. The Darcy fluid flow during compaction is described by an advection‐diffusion equation for the excess pressure with two source/sink terms that depend on the mechanical compressibility and viscous compaction of the pore space, the latter representing the effect of pressure solution. The incompressible deformation of the composite medium is described by a force balance equation and its rheology can be viscous, plastic, or viscoplastic (Bingham material). For the plastic and viscoplastic cases, the coupling between the compacting and plastically deforming parts of the system is through the Drucker‐Prager frictional‐plastic yield criterion modified by Terzaghi's principle, so that the yield strength depends on the effective dynamical pressure. The coupled system is solved using a two‐dimensional (2‐D) finite element method. Two problems are solved to demonstrate the behavior of our theory. The first considers compaction of a uniform sediment layer. The numerical results agree with the predictions of the nondimensional control parameters and previously published results. The second problem concerns 2‐D kinematic progradation of deltaic sediments. Substratum and delta sediments have the same compaction properties and a Bingham rheology during deviatoric deformation, such that the delta undergoes linear postyield viscous flow. For certain depositional regimes, overpressure is generated. When pore pressures approach critical values, yielding occurs and the delta front fails and becomes unstable, spreading gravitationally under its own weight. The flow velocity is limited to geological rates by the Bingham viscosity. For the range of parameter values considered, pressure solution is the most effective mechanism for generating near‐lithostatic fluid pressures that lead to initial failure, and it appears that mechanical compaction hardly contributes to the fluid overpressure at this stage.
On the origin and significance of subadiabatic temperature gradients in the mantle
Authors: Sinha G. , Butler S. L.
Published: October 2007

It is well established that the temperature gradients in the interiors of internally heated mantle convection models are subadiabatic. The subadiabatic gradients have been explained as arising because of a balance between vertical advection and internal heating; however, a detailed analysis of the energy balance in the subadiabatic regions has not been undertaken. In this paper, we examine in detail the energy balance in a suite of simple, two‐dimensional convection calculations with mixed internal and basal heating, depth‐dependent viscosity, and continents. We find that there are three causes of subadiabatic gradients. One is the above mentioned balance, which becomes significant when the ratio of internal heating to total surface heat flow is large. The second mechanism involves the growth of the “overshoot” of the geotherm near the lower boundary where the dominant balance is between vertical and horizontal advection. The latter mechanism is significant even in relatively weakly internally heated calculations. For time‐dependent calculations, we find that local secular cooling can be a dominant term in the energy equation and can lead to subadiabaticity. However, it does not show its signature on the shape of the time‐averaged geotherm. We also compare the basal heat flow with parameterized calculations based on the temperature drop at the core‐mantle boundary, calculated both with and without taking the subadiabatic gradient into account, and we find a significantly improved fit with its inclusion.
Diffraction by a wedge with a face of variable impedance
Authors: Budaev Bair V. , Bogy David B.
Published: October 2007

The two‐dimensional problem of diffraction by a wedge with a face of variable impedance is explicitly solved by a probabilistic random walk method. The solution admits numerical simulation based on simple scalable algorithms with unlimited capability for parallel processing. The diffracted field is represented as a mathematical expectation of a specified functional on trajectories of random motions determined by the configuration of the problem. The solution is not significantly more difficult than a similar probabilistic solution of the problem with constant impedance faces.
Effects of temperature and precipitation trends on U.S. drought
Authors: Easterling David R. , Wallis Trevor W. R. , Lawrimore Jay H. , Heim Richard R.
Published: October 2007

The contiguous United States has experienced both warming temperatures and a general increase in precipitation during the period 1950–2006. During that time drought has been a recurring phenomenon with a number of large droughts occurring, starting with the major drought in the 1950s in the Central United States and culminating with the persistent drought in the western portion of the country that started in the late 1990s. Here we examine the influence of the multi‐decadal warming trend on drought coverage and the possibility that the general increase in regional and contiguous U.S. precipitation since about 1980 has masked the tendency for increasing drought driven largely by increasing temperature. Results indicate that without the increase in precipitation, severe to extreme drought would have affected as much as 50% more of the U.S. during some months in the most recent drought period.
Stability study of planar targets using standard and adiabat shaping pulses
Authors: Olazabal-Loumé M. , Hallo L.
Published: October 2007

The hydrodynamic stability of a planar target is considered for the conditions of the direct drive inertial confinement fusion. It has been recently proposed to reduce the ablative Rayleigh-Taylor instability growth by using the adiabat shaping in the ablation zone. In this work, we consider the relaxation adiabat shaping scheme [K. Anderson and R. Betti, Phys. Plasmas 11, 5 (2004); R. Betti, K. Anderson, J. P. Knauer, T. J. B. Collins, R. L. McCrory, P. W. McKenty, and S. Skupsky, Phys. Plasmas 12, 042703 (2005)]. In this scheme, a prepulse (“picket”) is followed by a relaxation period, when the laser is turned off. A parametric study of picket parameters is performed with a code dedicated to the linear stability analysis on the basis of spherical realistic simulations including full physics. The influence of the picket parameters is investigated numerically. Simulations show that the set picket/relaxation time mainly determines the target stability and that the adiabat shaping scheme modifies the perturbed state before the main acceleration. In particular, the perturbed density level is reduced in the cases studied. Finally, several planar configurations have been used to look into the details of perturbation growth. It has been found that stabilization increases with prepulse intensity at the beginning of the acceleration phase.
An inertial range model for the three-point third-order velocity correlation
Authors: Chang Henry , Moser Robert D.
Published: October 2007

It is noted that in large eddy simulation (LES), filtering of the three-point third-order velocity correlation allows one to determine the two-point third-order correlation of the filtered velocity. This is useful in analyzing the dynamics of filtered (LES) fields, since the two-point third-order correlation describes energy flux from large to small scales, just as it does in unfiltered turbulence. A model for the three-point third-order correlation for stationary, incompressible, homogeneous, isotropic turbulence in the inertial range is proposed in which simple polynomials are used as the scalar function appearing in the most general tensorial form for the correlation. This leads to a model with four free parameters, which are set by appealing to statistical data from a direct numerical simulation. The resulting three-point third-order correlation function is in very good agreement with the data.
Low leakage Schottky rectifiers fabricated on homoepitaxial GaN
Authors: Lu Hai , Zhang Rong , Xiu Xiangqian , Xie Zili , Zheng Youdou , Li Zhonghui
Published: October 2007

The development of a vertical GaN Schottky rectifier on freestanding bulk GaN substrate by employing homoepitaxial growth technique is reported. The n−∕n+ Schottky diode structure was grown on conductive GaN substrate by metal-organic chemical vapor deposition. The dislocation density of the homoepitaxial layer determined by cathodoluminescence mapping technique is ∼6×106cm−2 with surface roughness less than 1nm. The fabricated Schottky rectifiers with dielectric overlap edge termination show a low reverse leakage current of <3×10−8A at −100V, which can be explained by the low dislocation density in the epilayer and high Schottky barrier height (1.37eV) of the Pt∕GaN metal-semiconductor contact. Due to the reduced series resistance, the bulk GaN Schottky rectifiers also exhibit a low turn-on voltage of ∼1.3V and an on-resistance of ∼5.3mΩcm2.
Bifurcation in electrostatic resistive drift wave turbulence
Authors: Numata Ryusuke , Ball Rowena , Dewar Robert L.
Published: October 2007

The Hasegawa-Wakatani equations, coupling plasma density, and electrostatic potential through an approximation to the physics of parallel electron motions, are a simple model that describes resistive drift wave turbulence. Numerical analyses of bifurcation phenomena in the model are presented, that provide new insights into the interactions between turbulence and zonal flows in the tokamak plasma edge region. The simulation results show a regime where, after an initial transient, drift wave turbulence is suppressed through zonal flow generation. As a parameter controlling the strength of the turbulence is tuned, this zonal-flow-dominated state is rapidly destroyed and a turbulence-dominated state re-emerges. The transition is explained in terms of the Kelvin-Helmholtz stability of zonal flows. This is the first observation of an upshift of turbulence onset in the resistive drift wave system, which is analogous to the well-known Dimits shift in turbulence driven by ion temperature gradients.
Nonlinear localized dust acoustic waves in a charge varying dusty plasma with nonthermal ions
Authors: Tribeche Mouloud , Amour Rabia
Published: October 2007

A numerical investigation is presented to show the existence, formation, and possible realization of large-amplitude dust acoustic (DA) solitary waves in a charge varying dusty plasma with nonthermal ions. These nonlinear localized structures are self-consistent solutions of the collisionless Vlasov equation with a population of fast particles. The spatial patterns of the variable charge DA solitary wave are significantly modified by the nonthermal effects. The results complement and provide new insights into previously published results on this problem.
Thick film laser induced forward transfer for deposition of thermally and mechanically sensitive materials
Authors: Kattamis Nicholas T. , Purnick Priscilla E. , Weiss Ron , Arnold Craig B.
Published: October 2007

Laser forward transfer processes incorporating thin absorbing films can be used to deposit robust organic and inorganic materials but the deposition of more delicate materials has remained elusive due to contamination and stress induced during the transfer process. Here, we present the approach to high resolution patterning of sensitive materials by incorporating a thick film polymer absorbing layer that is able to dissipate shock energy through mechanical deformation. Multiple mechanisms for transfer as a function of incident laser energy are observed and we show viable and contamination-free deposition of living mammalian embryonic stem cells.
The dissociative adsorption of silane and disilane on Si(100)-(2×1)
Authors: Shi J. , Tok E. S. , Kang H. Chuan
Published: October 2007

We investigate the dissociative adsorption of silane and disilane on Si(100)-(2×1) using pseudopotential planewave density functional theory calculations. These are important steps in the growth of silicon films. Although silane has been studied computationally in some detail previously, we find physisorbed precursor states for the intradimer and interdimer channels. The silane energetics calculated here are in good agreement with experimental data and previous theoretical estimates and provide us with a useful reference point for our disilane calculations. Disilane has not been studied as intensively as silane. We investigate both silicon–silicon bond cleavage and silicon–hydrogen bond cleavage mechanisms, and for each we investigate intradimer, interdimer, and inter-row channels. As in the case of silane, we also find precursor states in the adsorption path in agreement with molecular beam experiments. The qualitative picture that emerges is that adsorption takes place through a weakly bound precursor state with a transition state to chemisorption that is low lying in energy relative to the gas phase. This is in good agreement with experimental data. However, the calculated energetics are only in fair agreement with experiments, with our transition state to chemisorption being about 0.02eV above the gas phase while experimentally it is estimated to be approximately 0.28eV below the gas phase. This suggests that accurate theoretical characterization of these weakly bound precursor states and the adsorption barriers requires further computational work.
Thermal diagnostics front-end electronics for LISA Pathfinder
Authors: Sanjuán J. , Lobo A. , Nofrarias M. , Ramos-Castro J. , Riu P. J.
Published: October 2007

Precision temperature measurements are required in the LTP, the LISA technology package, for various diagnostics objectives. In this article, we describe in detail the front-end electronics design and the associated temperature sensors to achieve the LTP requirements: noise equivalent temperature of 10μKHz−1∕2 in the frequency range from 1to30mHz at room temperature. We designed an ac Wheatstone bridge and a subsequent digital demodulation to minimize 1∕f noise. We show experimental results where the required sensitivity in the measurement bandwidth is fulfilled.
Multiscale vulnerability of complex networks
Authors: Boccaletti Stefano , Buldú Javier , Criado Regino , Flores Julio , Latora Vito , Pello Javier , Romance Miguel
Published: October 2007

We present a novel approach to quantify the vulnerability of a complex network, i.e., the capacity of a graph to maintain its functional performance under random damages or malicious attacks. The proposed measure represents a multiscale evaluation of vulnerability, and makes use of combined powers of the links’ betweenness. We show that the proposed approach is able to properly describe some cases for which earlier measures of vulnerability fail. The relevant applications of our method for technological network design are outlined.
Impact of interfacial dipole on effective work function of nickel fully silicided gate electrodes formed on rare-earth-based dielectric interlayers
Authors: Lim Andy Eu-Jin , Fang Wei-Wei , Liu Fangyue , Lee Rinus Tek Po , Samudra Ganesh , Kwong Dim-Lee , Yeo Yee-Chia
Published: October 2007

The mechanism underlying the modulation of nickel fully silicided (Ni-FUSI) gate work function Φm by rare-earth (RE)-based dielectric interlayers (RE: Y, Er, Dy, Tb, Yb, and La) was investigated. RE–O–Si bonding in these ultrathin (∼1nm) interlayers induces highly polarized RE–O bonds at the gate/dielectric interface. The relative magnitude of the RE–O dipole was estimated from the product of the net electronegativity difference and the charge separation between the RE and O ions. Excellent correlation of the modulated Ni-FUSI Φm with the calculated dipole moment was shown. The proposed quantitative interfacial dipole model could be used for the selection of interlayer materials for further Φm optimization and precise control of threshold voltage in transistors.