bluuebunny/crossref_metadata_2025 huggingface dataset:
Carrier capture and escape processes in (In,Ga)N single‐quantum‐well diode under forward bias condition by photoluminescence spectroscopy
Authors: Satake A. , Soejima K. , Aizawa H. , Fujiwara K.
Published: May 2006

Carrier capture and escape processes in the super‐bright green (In,Ga)N single‐quantum‐well (SQW) light‐emitting diode (LED) has been studied by photoluminescence (PL) spectroscopy under reverse and forward bias conditions. The PL spectra were measured at 20 K under excitation photon energies above and below the bandgap energy of GaN barrier layers. The PL spectra under both excitation conditions show green emission from the (In,Ga)N SQW layer. The wavelength‐integrated PL intensity changes drastically depending on the applied bias voltage. For the excitation below the bandgap energy of GaN (direct excitation), the PL intensity increases with increasing the forward bias voltage up to +2 V and significant reduction of the PL intensity is observed with further increase of the forward bias voltage. On the other hand, for the excitation above the bandgap energy of GaN (indirect excitation), the PL intensity rapidly increases up to +2 V, decreases once, increases again with the maximum value at +3.25 V, and drastically decreases again. These differences of the PL intensity variation reflect carrier escape and capture processes. That is, for the direct excitation condition, the PL intensity variation indicates the effect of the electric field on the radiative recombination and the carrier escape processes. In contrast, for the indirect excitation condition, it indicates the carrier transfer and capture processes. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Barrier‐to‐well carrier dynamics of InGaN/GaN multi‐quantum‐wells grown by plasma assisted MBE on bulk GaN substrates
Authors: Korona K. P. , Skierbiszewski C. , Siekacz M. , Feduniewicz A. , Suski T. , Franssen G. , Grzegory I. , Borysiuk J. , Leszczyński M.
Published: May 2006

We present study of carrier dynamics in GaInN/GaN multi quantum wells (MQWs) with screened electric fields. The PL emission showed clearly resolved peaks emitted from the Ga0.9In0.1N QWs (at about 3.1 eV, FWHM 30‐50 meV). Two samples with 2.5‐nm‐QWs and 4‐nm‐QWs showed decay‐times of 1.1 ns and 2.3 ns. The decay‐rates in the barriers were thermally activated, activation energies were 21 meV and 46 meV, for the 2.5‐nm‐QWs and 4‐nm‐QWs structures, respectively. Analysis of correlation between rising‐rates of the MQW PL and the decay‐rates of the barriers PL confirmed increase of transport through barrier. The MQW PL energy changed with time. The phenomenon was due to trapping of excitons on donors or localization in potential minima. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum kinetic theory of phonon‐assisted carrier transitions in nitride based quantum‐dot systems
Authors: Seebeck J. , Nielsen T.R. , Lorke M. , Gartner P. , Jahnke F.
Published: May 2006

A microscopic theory for the interaction of carriers with LO phonons is used to study ultrafast capture and relaxation dynamics in semiconductor quantum dots. Energy renormalization due to carrier‐phonon interaction leads to quantum‐dot polarons which are included in quantum‐kinetic equations to describe scattering processes. Our results show efficient capture and relaxation processes. For an InGaN quantumdot system the influence of the strong built‐in electrostatic field on the carrier dynamics is investigated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Leveraging disposable instrumentation to reduce coverage collection overhead
Authors: Chilakamarri Kalyan‐Ram , Elbaum Sebastian
Published: May 2006

Testers use coverage data for test suite quality assessment, stopping criteria definition, and effort allocation. However, as the complexity of products and testing processes increases, the cost of coverage data collection may grow significantly, jeopardizing its potential application. To mitigate this problem this paper presents the concept of ‘disposable coverage instrumentation’—coverage instrumentation that is removed after its execution—through two techniques: local disposal, and collective disposal. A Java virtual machine was extended to support these techniques, and their potential is shown through two studies utilizing the Specjvm98 and Specjbb2000 benchmarks. The results indicate that the techniques can reduce coverage collection overhead by an order of magnitude over state‐of‐the‐art techniques. Copyright © 2006 John Wiley & Sons, Ltd.
One‐stage Sigmoid Colon Resection for Perforated Sigmoid Diverticulitis (Hinchey Stages III and IV)
Authors: Richter Sven , Lindemann Werner , Kollmar Otto , Pistorius Georg A. , Maurer Christoph A. , Schilling Martin K.
Published: May 2006

Introduction

Guidelines for the treatment of complicated sigmoid diverticulitis recommend Hartmann’s procedure or anastomosis with protective colostomy for Hinchey stage III diverticulitis and Hartmann’s procedure only for Hinchey stage IV diverticulitis. We evaluated the outcome of patients with perforated sigmoid diverticulitis Hinchey III/IV undergoing one‐stage colon resection and primary anastomosis without protective colostomy.

Methods

After implementation of a protocol to treat Hinchey III/IV diverticulitis with primary anastomosis without protective ileocolostomy, the patients’ data were recorded prospectively between August 2001 and August 2003 and analyzed retrospectively from a computer‐related database.

Results

Of 41 patients, 34 (81%%) underwent one‐stage sigmoid resection and primary anastomosis, 3 of 41 patients (7%%) underwent primary anatomosis with protective ileostomy, and 5 of 41 patients (12%%) had a Hartmann’s procedure. The mortality was 11%% in patients undergoing primary anastomosis and 60%% in patients with Hartmann’s procedure. The relative risk of co‐morbidity factors for lethal outcome after sigmoid resection was 6.94 for preceding operations, 3.75 for renal failure or renal transplantation, and 3.25 for immunosuppression.

Conclusions

One‐stage sigmoid resection and primary anastomosis can be performed safely in nearly 90%% of all patients with perforated sigmoid diverticulitis (Hinchey III/IV) by surgeons of different training levels. Patients with immunosuppression, chronic renal failure, liver cirrhosis, or previous organ transplantation or complex cardiovascular reconstructive procedures have a significantly increased risk of dying after sigmoid resection for perforated diverticulitis.
The Cryptothecia candida complex revisited
Authors: LÜCKING Robert , THOR Göran , APTROOT André , KALB Klaus , ELIX John A.
Published: May 2006

Revision of world-wide material of Cryptothecia candida sensu Santesson (1952) revealed that three different species are involved, differing in the shape of their ascomata, chemistry, and distribution. C. candida (Kremp.) R. Sant. s. str. [syn.: Arthonia lacerata Vain.; C. epiphylla R. Sant.] contains 2′-O-methylperlatolic acid and 2′-O-methylanziaic acid (thallus and ascomata C+ red) and has rounded to slightly irregular ascomata; it is a paleotropical species occurring in Africa and SE Asia (absent in Australia). All neotropical populations previously identified as C. candida contain perlatolic acid (thallus and ascomata C−) and are further characterized by their well-delimited, regularly rounded ascomata. The name Cryptothecia filicina (Ellis & Everh.) Lücking & G. Thor comb. nov. [bas.: Ascomycetella filicina Ellis & Everh.; syn.: Myxotheca hypocreoides Ferd. & Winge] is taken up for this taxon. A third species was discovered in material from Australia and China (Hong Kong) and is here described as Cryptothecia irregularis Lücking, Aptroot, Kalb & Elix sp. nov. Its ascomata are radiately elongate and it contains psoromic, subpsoromic, 2′-O-demethylpsoromic, and confluentic acids.
Ambient UV irradiation induces a blue pigment in Xanthoparmelia stenophylla
Authors: McEvoy Maria , Solhaug Knut Asbjørn , Gauslaa Yngvar
Published: May 2006

Lichens are colourful organisms owing to numerous combinations of algal and fungal pigments (as reviewed by Rikkinen 1995). Colour is often used in taxonomic studies to aid species identification but it is sometimes over-used as a characteristic to discriminate related genera such as, Xanthoparmelia and Neofuscelia (Poelt & Leuckert 1993). However, colour variations within species can be significant (Solhaug et al. 2003) because of spatial (Gauslaa & Solhaug 2001; Gauslaa & Ustvedt 2003) and temporal variations (Gauslaa & McEvoy 2005) in environmental factors. There are few experimental studies on lichen colours so far; as a result we do not know the relative importance of genetic versus environmental factors. Our study aimed to assess the effect of ultraviolet radiation (UVR) on the colour of the widespread foliose lichen Xanthoparmelia stenophylla (Ach.) Ahti & D. Hawksw. (until recently known as X. somloensis (Gyeln.) Hale, see Ahti & Hawksworth 2005). Usnic acid is responsible for the yellowish appearance of its upper cortex, but other colour variations are also mentioned in taxonomic literature (Brodo et al. 2001). More specifically, we wanted to discover if UVR and the photosynthate ribitol supplied by the photobiont would cause changes in pigmentation in a Xanthoparmelia species. These factors have been shown to induce and stimulate the synthesis of the orange parietin in Xanthoria parietina (Solhaug & Gauslaa 2004; Solhaug et al. 2003).
A new species of Lepraria (Lecanorales: Stereocaulaceae) from the Canary Islands and the typification of Lepraria isidiata
Authors: CRESPO Ana , ARGUELLO Arturo , LUMBSCH H. Thorsten , LLIMONA Xavier , TØNSBERG Tor
Published: May 2006

The new species Lepraria santosii Argüello & Crespo is described from the Canary Islands. It is characterized by a crustose to subsquamulose thallus with slightly raised rim and the presence of atranorin and the stictic acid chemosyndrome. It is currently known from Tenerife (Canary Islands), where it grows on soil over basaltic rocks in the laurel forest. Twelve new sequences of the ITS region from this species and L. isidiata were obtained and analysed with sequences downloaded from GenBank. Maximum parsimony and Bayesian analyses suggest that Lepraria santosii is closely related to L. isidiata. The latter name is here lectotypified and the characters for the distinction of the two species from similar taxa are discussed.
National enhanced surveillance of meningococcal disease in England, Wales and Northern Ireland, January 1999–June 2001
Authors: SHIGEMATSU M. , DAVISON K. L. , CHARLETT A. , CROWCROFT N. S.
Published: May 2006

Enhanced surveillance of meningococcal disease (ESMD) was implemented nationally across ten regions of England, Wales and Northern Ireland from 1 January 1999. It aims to deliver more sensitive surveillance than laboratory reporting by including clinically diagnosed but laboratory unconfirmed cases. Consultants in Communicable Disease Control (CsCDC) report all clinically diagnosed cases of meningococcal disease (MD) to the Regional Epidemiologist in the relevant regional unit of the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC). These reports are reconciled with laboratory data from the PHLS Meningococcal Reference Unit and then forwarded to the national CDSC where further reconciliation with laboratory data takes place. In addition, CsCDC are asked to report any clusters of MD that occur. Between 1 January 1999 and 30 June 2001, 12074 cases of MD were ascertained through ESMD. The majority (57%) were laboratory confirmed. The estimated incidence of MD fell between 1999 and 2001 from 9.2 to 8.0 per 100000 population. Of laboratory confirmed cases, the number of cases of serogroups B and W135 increased and of serogroup C and of ungrouped meningococcal infection decreased. Variation between regions was considerable and deserves further investigation. Of 11522 cases with a reported clinical diagnosis, 53.6% were diagnosed as septicaemia, 32.6% as meningitis, 12.5% as both septicaemia and meningitis, and 1.3% had other invasive MD. Between 1 January 1999 and 30 June 2001 698 deaths were reported, an overall case fatality rate (CFR) of 5.8%; 567 deaths were in confirmed cases and 131 probable (CFR 8.2% and 2.5%, respectively). CFR was higher in serogroup C (13.5%) than B (5.8%). No peak in serogroup C meningococcal infection occurred in the winter of 2000/1 and no clusters of serogroup C meningococcal infection were reported in the first half of 2001. ESMD provides information about the epidemiology of MD that is more complete than statutory notification and laboratory surveillance and is useful for evaluating the impact of the meningococcal serogroup C vaccination programme and of the other non-vaccine preventable serogroups.
Is household antibiotic use a risk factor for antibiotic-resistant pneumococcal infection?
Authors: KWAN-GETT T. S. , DAVIS R. L. , SHAY D. K. , BLACK S. , SHINEFIELD H. , KOEPSELL T.
Published: May 2006

We used microbiology and pharmacy data from health-maintenance organizations to determine whether antibiotic use by a household member increases the risk of penicillin-non-susceptible pneumococcal disease. Though it has been well established that an individual's antibiotic use increases one's risk of antibiotic-resistant infection, it is unclear whether the risk is increased if a member of one's household is exposed to antibiotics. We therefore conducted a case-control study of patients enrolled in health maintenance organizations in Western Washington and Northern California. Cases were defined as individuals with penicillin-non-susceptible pneumococcal infection; controls were individuals with penicillin-susceptible pneumococcal infection. Socioeconomic variables were obtained by linking addresses with 1997 census block group data. One-hundred and thirty-four cases were compared with 798 controls. Individual antibiotic use prior to diagnosis increased the odds of penicillin non-susceptibility, with the strongest effect seen for β-lactam use within 2 months (OR 1·8, 95% CI 1·2, 2·8). When household antibiotic use by persons other than the patient were considered, at 4 months prior to diagnosis there was a trend towards an association between penicillin non-susceptibility and β-lactam antibiotic use, and a possible association in a small subgroup of patients with eye and ear isolates. However, no significant overall pattern of association was seen. We conclude that though antibiotic use of any kind within 2 months prior to diagnosis is associated with an increased risk of penicillin-non-susceptible pneumococcal disease, there is no significant overall pattern of association between household antibiotic use and penicillin-non-susceptible pneumococcal infection.
Number of deaths among HIV-infected adults in France in 2000, three-source capture–recapture estimation
Authors: LEWDEN C. , JOUGLA E. , ALIOUM A. , PAVILLON G. , LIÈVRE L. , MORLAT P. , SALMON D. , MAY T. , CHÊNE G. , COSTAGLIOLA D.
Published: May 2006

We estimated the number of deaths in France for the year 2000 in HIV-infected adults using three sources. The sources were (1) the ‘Mortalité 2000’ survey (M2000): 964 deaths were documented by 185 hospital wards involved in HIV management; (2) 1288 death certificates with a mention of HIV infection (INSERM-CepiDc) and (3) the French hospital database on HIV infection (FHDH) identified 654 deaths. The capture–recapture method was used with log-linear modelling. Overall 1559 deaths were observed. Estimation of the number of deaths in France was 1699 (95% CI 1671–1727). The completeness of M2000, CepiDc and FHDH were 55%, 76% and 38% respectively. Diversification of diseases and of causes of death in HIV-infected adults may explain: (1) the diversification of physicians involved in their management and incomplete coverage of M2000 and FHDH, and (2) why HIV infection was not mentioned in all death certificates.
A PRIMER SET FOR SPECIFIC AMPLIFICATION OF TWO CYCLOIDEA-LIKE GENES IN THE GENISTOID CLADE OF LEGUMINOSAE SUBFAM. PAPILIONOIDEAE
Authors: CITERNE H. L.
Published: May 2006

Locus-specific primers were designed to amplify the homologues LEGCYC1A and LEGCYC1B of the snapdragon (Antirrhinum majus) floral symmetry gene CYCLOIDEA in the genistoid legumes Lupinus nanus and Cadia purpurea. These primers were tested successfully in a range of genistoid taxa. Sequence comparison between L. nanus and L. angustifolius revealed that these CYCLOIDEA-like genes provide up to four times as many variable characters as the ribosomal internal transcribed spacers (ITS) at this taxonomic level. These genes are therefore potentially useful for studying evolutionary relationships between closely related species within the genistoid clade of legumes, which contains many large and diverse genera. Comparisons between L. nanus, Cadia purpurea and Calpurnia aurea LEGCYC sequences show that these genes may also be useful for phylogenetic studies between genera in this large clade of 1800 species.
A NEW TURKISH SPECIES OF COLCHICUM (COLCHICACEAE) RELATED TO C. BOISSIERI
Authors: PERSSON K.
Published: May 2006

A new species, Colchicum chlorobasis (Colchicaceae), endemic to S Turkey, is described. The species is related to C. boissieri but differs mainly in having a larger, more rounded corm with only short lobes, browner more evanescent tunics projecting along the cataphyll, and more leaves. Both have greenish filament bases. Comparisons are also made with C. sieheanum and C. baytopiorum. A key and illustrations are provided to distinguish these four species, and their distribution is shown on a map. Chromosome numbers have been determined for C. chlorobasis, C. boissieri and C. baytopiorum.
Bismuth-zinc-niobate embedded capacitors grown at room temperature for printed circuit board applications
Authors: Park Jong-Hyun , Lee Woo-Sung , Seong Nak-Jin , Yoon Soon-Gil , Son Seung-Hyun , Chung Hyung-Mi , Moon Jin-Suck , Jin Hyun-Joo , Lee Seung-Eun , Lee Jeong-Won , Kang Hyung-Dong , Chung Yeoul-Kyo , Oh Yong-Soo
Published: May 2006

We fabricated metal-insulator-metal (MIM) thin film capacitors with Bi1.5Zn1.0Nb1.5O7 (BZN) dielectric films. The BZN films were deposited at room temperatures by pulsed laser deposition and annealed below 200°C which is compatible with the used polymer-based substrates. The dielectric constant of BZN films increases from 2 to 70, when they are annealed at 150°C, but still in amorphous phase. We found that a considerable portion of Bi metallic phase still remains in the as-deposited film. They turn into oxides upon annealing at >120°C, causing the dramatic change of the dielectric properties. Amorphous BZN thin films exhibit superior dielectric characteristics, capacitance density of 150nF∕cm2, and leakage current less than 1μA∕cm2 at 5V. The MIM capacitors using amorphous BZN thin films will be a promising candidate for the PCB-embedded capacitors.
Synthesis and characterization of one-dimensional CdSe nanostructures
Authors: Wang G. X. , Park M. S. , Liu H. K. , Wexler D. , Chen J.
Published: May 2006

One-dimensional (1D) CdSe nanostructures, including nanowires, nanotubes, nanorods, nanobelts, and even nanostructures resembling saws and tree branches, have been synthesized by sublimation of CdSe powders under various experimental conditions. These 1D CdSe nanostructures were characterized by scanning electron microscopy, high resolution transmission electron microscopy observations, and Raman spectroscopy. Energy dispersive x-ray spectroscopy analysis confirmed the chemical stoichiometry of the CdSe nanostructures. It was found that the geometrical morphologies of the CdSe 1D nanostructures were significantly influenced by the synthetic parameters. Raman spectra of CdSe nanowires show an upward shift of the 2LO phonon peak.
Energetic and magnetic properties of transition-metal nanowire encapsulated BxCyNz composite nanotubes
Authors: Peng G. W. , Huan A. C. H. , Feng Y. P.
Published: May 2006

We present a comparative study on the structural, energetic, and magnetic properties of carbon and BxCyNz composite single-walled nanotubes filled with transition-metal (TM) nanowires using first-principles calculations. It was found that interaction between the nanotube and nanowire weakens the magnetism of the nanowire. TM∕BC3 was found exceptionally stable and its formation is exothermic. The resulting hybrid structure, however, has the weakest magnetism compared to other systems for the same tube size. Similar to hybrid structures based on carbon and BN nanotubes, both TM∕BC2N and TM∕BC3 hybrid structures show high spin polarization which may have potential applications in spintronics.
All-optical pulse data generation in a semiconductor optical amplifier gain controlled by a reshaped optical clock injection
Authors: Lin Gong-Ru , Chang Yung-Cheng , Yu Kun-Chieh
Published: May 2006

Wavelength-maintained all-optical pulse data pattern transformation based on a modified cross-gain-modulation architecture in a strongly gain-depleted semiconductor optical amplifier (SOA) is investigated. Under a backward dark-optical-comb injection with 70% duty-cycle reshaping from the received data clock at 10GHz, the incoming optical data stream is transformed into a pulse data stream with duty cycle, rms timing jitter, and conversion gain of 15%, 4ps, and 3dB, respectively. The high-pass filtering effect of the gain-saturated SOA greatly improves the extinction ratio of data stream by 8dB and reduces its bit error rate to 10−12 at −18dBm.
Dislocation filtering by AlxIn1−xSb∕AlyIn1−ySb interfaces for InSb-based devices grown on GaAs (001) substrates
Authors: Mishima T. D. , Edirisooriya M. , Goel N. , Santos M. B.
Published: May 2006

Dislocation filtering by interfaces between AlxIn1−xSb and AlyIn1−ySb layers grown on a GaAs (001) substrate has been investigated. Transmission electron microscopy analysis shows that as many as 59% of threading dislocations (TDs) can be eliminated by such an interface. An interlayer sample that contains six Al0.12In0.88Sb∕Al0.24In0.76Sb interfaces has 6.0×108TDs∕cm2 at 1.6μm thickness. Compared with an Al0.12In0.88Sb epilayer without an interlayer, this TD density is a factor of ∼4 lower for the same thickness, and about the same as for a layer that is more than twice as thick. Our results suggest that AlxIn1−xSb∕AlyIn1−ySb interfaces can be used to improve the performance of any InSb-based device in which AlxIn1−xSb is used as a buffer, insulating, or barrier layer material.
Combination of known and unknown mechanisms confers high-level resistance to fluoroquinolones in Enterococcus faecium
Authors: Oyamada Yoshihiro , Ito Hideaki , Fujimoto Kouichi , Asada Reiko , Niga Toshiyuki , Okamoto Ryoichi , Inoue Matsuhisa , Yamagishi Jun-ichi
Published: May 2006

In order to elucidate the mechanisms of fluoroquinolone resistance in Enterococcus faecium, spontaneous mutants isolated from Ent. faecium ATCC 19434 by stepwise selection with sparfloxacin (SPX) or norfloxacin (NOR) and 13 clinical isolates of Ent. faecium were characterized by analysing quinolone-resistance-determining regions (QRDRs) of the gyrA, gyrB, parC and parE genes and examining changes in MICs of SPX and NOR in the presence of efflux pump inhibitors. The SPX-selected first-step mutant had a point mutation only in gyrA, and the mutants QR7-18 and QR7-39, and clinical isolates that had point mutations in parC, showed NOR resistance. These results indicate that the primary targets of SPX and NOR are DNA gyrase and topoisomerase IV, respectively, and therefore that the primary target of fluoroquinolones in Ent. faecium differs depending on the structure of the compound used. The characterization of the spontaneous mutants and the clinical isolates demonstrates that in addition to the previously reported alterations in GyrA and ParC, an alteration in GyrB, a NorA-like pump, an unknown efflux pump, which excretes both SPX and NOR from bacterial cells, and probably other unknown mechanism(s) all contribute to fluoroquinolone resistance in Ent. faecium.
Basis for N-acetyllactosamine-mediated inhibition of enteropathogenic Escherichia coli localized adherence
Authors: Hyland Romney M. , Griener Thomas P. , Mulvey George L. , Kitov Pavel I. , Srivastava Om P. , Marcato Paola , Armstrong Glen D.
Published: May 2006

In a previous article, the authors reported that exposing wild-type enteropathogenic Escherichia coli (EPEC) to chemically synthesized N-acetyllactosamine glycosides covalently coupled to BSA (LacNAc–BSA) inhibited localized adherence (LA) by these organisms and also caused them to lose their bundle-forming pili (BFP), the filamentous surface appendages responsible for their LA phenotype. This effect has now been further investigated by screening a panel of LacNAc–BSA-related glycosides for their ability to inhibit EPEC LA, which revealed that LacNAc–BSA retained its status as the most effective inhibitor of EPEC LA. It was also shown that LacNAc–BSA did not cause the loss of BFP in an EPEC strain containing a non-polar mutation in the bfpF gene and, as a consequence, unable to retract its BFP. LacNAc–BSA also effectively inhibited LA of the bfpF mutant EPEC. Taken together, these observations suggest that, as well as triggering BfpF-mediated BFP retraction, LacNAc–BSA likely functions as a competitive inhibitor of EPEC binding to LacNAc-related receptors on host cells. Moreover, transmission electron microscopy revealed that LacNAc conjugated to gold nanoparticles bound specifically to BFP. This observation indicated that either the major BFP structural subunit (BfpA) itself or, possibly, an accessory protein co-assembled with BfpA into the BFP filaments, contains a LacNAc-specific EPEC adhesin. The results suggest a mechanism whereby the initial binding of EPEC to LacNAc-like receptors on host cells triggers BfpF-mediated BFP retraction. This could then expedite the intimate adherence phase of the multi-step EPEC colonization process by drawing the organisms closer to the host-cell plasma membrane.
Leptospirosis-induced meningitis and acute renal failure in a 19-month-old male child
Authors: de Souza Alexandre Leite , Sztajnbok Jaques , Marques Silvia Regina , Seguro Antonio Carlos
Published: May 2006

An unusual case of leptospirosis is described in a 19-month-old male child presenting with meningitis and acute renal failure without jaundice. Some aspects concerning the pathogenesis and treatment of this potentially life-threatening disease are also discussed. Leptospirosis was diagnosed on the basis of history and serological tests.
Genotyping of human papillomavirus in cervical lesions by L1 consensus PCR and the Luminex xMAP system
Authors: Jiang Han-Liang , Zhu Hai-Hong , Zhou Lin-Fu , Chen Feng , Chen Zhi
Published: May 2006

Infection with human papillomavirus (HPV) is the main cause of cervical cancer, the principal cancer in women in most developing countries. Molecular epidemiologic evidence clearly indicates that certain types of HPV are the principal cause of invasive cervical cancer and cervical intraepithelial neoplasia. Comprehensive, high-throughput typing assays for HPV, however, are not currently available. By combining L1 consensus PCR and multiplex hybridization using a Luminex xMAP system-based suspension array, the authors developed a rapid high-throughput assay, the HPV DNA suspension array (HPV-SA), capable of simultaneously typing 26 HPVs, including 18 high-risk HPV genotypes and eight low-risk HPV genotypes. The performance of the HPV-SA applied to 26 synthetic oligonucleotide targets was evaluated. The HPV-SA system perfectly discriminated 18 high-risk HPV targets from eight low-risk HPV targets. To assess the clinical applicability of the assay, the HPV-SA was performed with 133 MY09/MY11 primer set-mediated PCR (MY-PCR)-positive clinical specimens; of the 133 samples, 121 were positive by HPV-SA. Both single and multiple types were easily identified. The authors believe that improvement of the assay may be useful for epidemiological studies, cancer-screening programmes, the monitoring of therapeutic interventions, and the evaluation of the efficacy of HPV vaccine trials.
Self‐reported skin exposure – a population‐based study
Authors: Anveden Ingegärd , Wrangsjö Karin , Järvholm Bengt , Meding Birgitta
Published: May 2006

The aim was to study self‐reported skin exposure in individuals from the general population with or without hand eczema. In a population‐based study in 1996 using postal questionnaires to 3000 individuals, 215 of 2218 (9.7%) reported hand eczema during the past 12 months. 182 (85%) of those with hand eczema and 182 without hand eczema, matched for age and sex, participated in telephone interviews in 1997 regarding exposure to skin irritants at work and in leisure time. No differences were shown in occupational exposure to water, hand washing or chemicals in individuals with or without hand eczema. Women reported more wet exposure than men at work and in leisure time. A correlation was found between occupational wet exposure and wet work at home. Persons in high‐risk occupations reported more frequent exposure to skin irritants. However, 53% in high‐risk occupations reported exposure to water and detergents for less than half‐hour a day and 11% in low‐risk occupations for more than half‐hour a day. In conclusion, individuals with or without hand eczema seem to have similar exposure to skin irritants. Using job titles as a proxy for exposure gives misclassification, which may result in underestimation of the hand eczema risk.
Stock Market Fluctuations and Money Demand in Italy, 1913–2003
Authors: Caruso Massimo
Published: May 2006

This paper examines the impact of stock market fluctuations on money demand in Italy from a long‐run perspective. The money demand function estimated by Muscatelli and Spinelli (2000) for a long time span is utilized as a benchmark, adding to the specification information on share prices from the Milan Stock Exchange Reform of 1913 to recent years. For a shorter time period (1938–2003), annual observations on stock market capitalization and turnover velocity are also considered. The empirical findings suggest that stock market fluctuations help to explain temporary movements in liquidity preference, rather than its secular patterns. Overall, a positive association emerges between an index of stock market prices that includes dividends and real money balances; however, the estimated long‐run relationship is unstable. In a dynamic, short‐term specification of money demand, the estimated coefficient of deflated stock prices is positive, and therefore compatible with a wealth effect, in the years 1913–1980, while in the last two decades a substitution effect has prevailed and the correlation between money and share prices has been negative. This is likely to reflect a change in financial structure and the increasing role of opportunity costs defined over a wider range of assets. These results are confirmed by data on stock market capitalization. Moreover, in the recent period, stock market turnover and money growth are positively correlated.
Raised plasma adiponectin levels in type 1 diabetic pregnancies
Authors: Randeva Harpal S. , Vatish Manu , Tan Bee K. , Qureshi Zubair , Boovalingam Padmabushan , Lewandowski Krzysztof C. , O’Hare Paul
Published: May 2006

Objectives  Adiponectin has antidiabetic properties. Our aim was to determine plasma adiponectin levels during pregnancy and postpartum (PP), in women with type 1 diabetic mellitus (T1DM) and nondiabetic (ND) women.

Patients and Methods  Fasting plasma adiponectin and leptin levels were measured in 20 ND and 19 T1DM women, at 20 and 30 weeks’ gestation, and 9 months’ PP. Insulin measurements were made in ND women.

Results  In both groups, after accounting for body mass index (BMI), leptin levels increased during pregnancy (P < 0·01) and were significantly higher than PP (P < 0·001). However, no significant differences in leptin levels were noted between both groups at any stage (P = 0·46). Conversely, adiponectin levels were higher in T1DM at all stages of the study (P < 0·001). A significant fall in adiponectin levels was seen between 20 and 30 weeks’ gestation in both groups (ND: P < 0·001; T1DM: P < 0·05); however, this decrease was attenuated in the T1DM group. Adiponectin levels PP were significantly higher than at 30 weeks (ND: P < 0·001; T1DM: P < 0·001). Furthermore, in T1DM, adiponectin appeared to correlate negatively with leptin, but only reached significance PP (r = –0·46, P < 0·001). In the ND group, adiponectin correlated negatively with both leptin (PP: r = −0·56, P < 0·0001) and insulin (P < 0·005).

Conclusions  Higher adiponectin levels were noted in T1DM throughout gestation compared to ND pregnancies, with no difference in leptin levels. The significance of these findings needs to be determined.
Consumer‐specific responses to riverine subsidy pulses in a riparian arthropod assemblage
Authors: PAETZOLD ACHIM , BERNET JACQUELINE F. , TOCKNER KLEMENT
Published: May 2006

1. Aquatic resource fluxes from streams can provide significant subsidies for riparian consumers. Because aquatic resource fluxes can be highly variable in space and time, the subsidy efficiency (i.e. transfer to the recipient food web) is controlled by the short‐term aggregative response of riparian consumers.

2. Field manipulations of stream‐derived invertebrate prey subsidies were used to examine specific aggregative responses of ground‐dwelling arthropods to riverine subsidy pulses in a braided‐river (Tagliamento River, NE Italy). Subsidy manipulation comprised short‐term reductions of natural stream‐derived subsidies and increased subsidies of stream‐derived invertebrate prey during four seasons.

3. We hypothesised that specific aggregative responses of riparian arthropods depend on their specialisation on aquatic insects which was inferred from stable isotope analysis. Natural riverine subsidy sources including aquatic insect emergence and surface‐drifting organisms were quantified.

4. Arthropods responded significantly with a reduction in abundance by 51%, at reduced subsidies and an increase by 110% at increased subsidies, when averaged over all seasons. Different arthropod taxa responded differently to subsidy manipulations in relation to their specialisation on aquatic subsidies: ground beetles with a diet consisting predominantly of aquatic insects responded only to subsidy reductions, indicating that their local abundance was not limited by natural stream‐derived subsidies; lycosid spiders with a partly aquatic diet showed no significant response; and ants, although relying on a terrestrial diet, responded positively to added stream‐derived invertebrate prey, indicating that stranding of surface‐drifting terrestrial invertebrates represented an important subsidy pathway.

5. Ground beetles and lycosid spiders were seasonally separated in their use of aquatic subsidies. Results indicate that the life‐history characteristics of riparian consumers can control the subsidy efficiency for the recipient community. By the effective uptake of pulsed riverine‐derived subsidies, riparian arthropods can enhance the transfer of riverine food sources to the riparian food web.
Elevated CO2 and tree fecundity: the role of tree size, interannual variability, and population heterogeneity
Authors: LADEAU SHANNON L. , CLARK JAMES S.
Published: May 2006

Long‐term population effects of changes in atmospheric CO2 will be largely determined by reproductive effort. Our research objectives were to quantify variability in seed production and rate of maturation among individual Pinus taeda L. (Pinaceae) trees growing in elevated CO2 (ambient plus 200 μL L−1) since 1996. Estimating tree fecundity in nature is frustrated by the difficulty of counting seeds from individual trees and the need for long‐term data. We have used a hierarchical Bayes approach to model individual tree fecundity, accounting for the complexity of experimentation in a natural setting over multiple years. The study presented here demonstrates large variability in natural fecundity rates and contributes to our understanding of how both interannual variation and population heterogeneity influence elevated CO2 effects. We found that trees growing under elevated CO2 matured earlier and produced more seeds and cones per unit basal area than ambient grown trees. By 2004, trees grown in high CO2 had produced an average 300 more seeds per tree than ambient grown trees. Although there was a trend toward decreasing mean CO2 effect (difference in fecundity between elevated and ambient treatments) over time, the hierarchical analysis indicates that this decrease comes from the emergence of a few highly fecund ambient grown trees by 2002, rather than acclimation or downregulation among the fumigated trees. The most important effect of increased CO2 in forest ecosystems may be the increase in fecundity reported here. Although biomass responses can sometimes be large, the increase in fecundity can have long‐term impacts on forest dynamics that transcend the current generation.
Estimates of soil respiration and net primary production of three forests at different succession stages in South China
Authors: YAN JUNHUA , WANG YINGPING , ZHOU GUOYI , ZHANG DEQIANG
Published: May 2006

Soil respiration (heterotropic and autotropic respiration, Rg) and aboveground litter fall carbon were measured at three forests at different succession (early, middle and advanced) stages in Dinghushan Biosphere Reserve, Southern China. It was found that the soil respiration increases exponentially with soil temperature at 5 cm depth (Ts) according to the relation Rg=a exp(bTs), and the more advanced forest community during succession has a higher value of a because of higher litter carbon input than the forests at early or middle succession stages. It was also found that the monthly soil respiration is linearly correlated with the aboveground litter carbon input of the previous month. Using measurements of aboveground litter and soil respiration, the net primary productions (NPPs) of three forests were estimated using nonlinear inversion. They are 475, 678 and 1148 g C m−2 yr−1 for the Masson pine forest (MPF), coniferous and broad‐leaf mixed forest (MF) and subtropical monsoon evergreen broad‐leaf forest (MEBF), respectively, in year 2003/2004, of which 54%, 37% and 62% are belowground NPP for those three respective forests if no change in live plant biomass is assumed. After taking account of the decrease in live plant biomass, we estimated the NPP of the subtropical MEBF is 970 g C m−2 yr−1 in year 2003/2004. Total amount of carbon allocated below ground for plant roots is 388 g C m−2 yr−1 for the MPF, 504 g C m−2 yr−1 for the coniferous and broad‐leaf MF and 1254 g C m−2 yr−1 for the subtropical MEBF in 2003/2004. Our results support the hypothesis that the amount of carbon allocation belowground increases during forest succession.
Downy mildew (Plasmopara viticola) epidemics on grapevine under climate change
Authors: FRANCESCA SALINARI , SIMONA GIOSUÈ , FRANCESCO NICOLA TUBIELLO , ANDREA RETTORI , VITTORIO ROSSI , FEDERICO SPANNA , CYNTHIA ROSENZWEIG , MARIA LODOVICA GULLINO
Published: May 2006

As climate is a key agro‐ecosystem driving force, climate change could have a severe impact on agriculture. Many assessments have been carried out to date on the possible effects of climate change (temperature, precipitation and carbon dioxide concentration changes) on plant physiology. At present however, likely effects on plant pathogens have not been investigated deeply. The aim of this work was to simulate future scenarios of downy mildew (Plasmopara viticola) epidemics on grape under climate change, by combining a disease model to output from two general circulation models (GCMs). Model runs corresponding to the SRES‐A2 emissions scenario, characterized by high projections of both population and greenhouse gas emissions from present to 2100, were chosen in order to investigate impacts of worst‐case scenarios, among those currently available from IPCC. Three future decades were simulated (2030, 2050, 2080), using as baseline historical series of meteorological data collected from 1955 to 2001 in Acqui Terme, an important grape‐growing area in the north‐west of Italy. Both GCMs predicted increase of temperature and decrease of precipitation in this region. The simulations obtained by combining the disease model to the two GCM outputs predicted an increase of the disease pressure in each decade: more severe epidemics were a direct consequence of more favourable temperature conditions during the months of May and June. These negative effects of increasing temperatures more than counterbalanced the effects of precipitation reductions, which alone would have diminished disease pressure. Results suggested that, as adaptation response to future climate change, more attention would have to be paid in the management of early downy mildew infections; two more fungicide sprays were necessary under the most negative climate scenario, compared with present management regimes. At the same time, increased knowledge on the effects of climate change on host–pathogen interactions will be necessary to improve current predictions.
The Xanadu project: training faculty in the use of information and communication technology for university teaching
Authors: Trentin G.
Published: May 2006

Abstract
Technology‐enhanced learning (TEL) methodologies are becoming an important part of University teaching but faculty members have tended to shy away from using them. So, how can they be enticed to use them effectively? What approaches can be used? The purpose of the Xanadu project was to analyse the problems involved and to propose a model for training, based on experimentation at the University of Turin. Besides providing a model, this article will deal with the follow‐up, particularly regarding the faculty members' initial approach to using information and communication technology (ICT), as well as examine the motives and conditions influencing their choices. In this sense, the project has enabled us to come to a better understanding of the typical misconceptions leading teachers to favour methodological approaches based on the distributive use of ICT (which are considered less demanding to manage), rather than networked collaborative interaction, which actually involve students more. In this regard, Xanadu has shown how teachers' awareness may be developed towards adopting a wide range of TEL approaches through both gradual training (project‐oriented with a basic and an advanced course) and with the help of a graduate assistant capable of following e‐content development and online collaborative activities. The effectiveness of the method may be confirmed by the large number of faculty members continuing to use ICT to support their teaching despite having no specific university TEL projects.
Making the cut: the impact of an integrated learning system on low achieving middle school students
Authors: O'Byrne B. , Securro S. , Jones J. , Cadle C.
Published: May 2006

Abstract
Research in integrated learning systems has demonstrated a need for rigorous studies that identify how such systems influence learning, and in particular that of low achieving students. No Child Left Behind legislation mandated evidence‐based interventions as the standard for instructional approaches in American public schools. This quasi‐experimental study investigated the impact of Merit literacy software on students in West Virginia. The study confirmed that the software supported the reading and language arts curriculum and significantly improved the scores of low achieving middle school students on three variables of the WESTEST, a criterion‐referenced state test: reading and language arts, science, and social science. This integrated learning system was effective with rural and urban school populations.
The role of TGF‐β in mice infected with Heligmosomoides polygyrus
Authors: DOLIGALSKA M. , RZEPECKA J. , DRELA N. , DONSKOW K. , GERWEL‐WRONKA M.
Published: May 2006

Hyporesponsiveness induced by Heligmosomoides polygyrus was quantified and the relationship between TGF‐β and inflammation was identified in BALB/c mice. The immune response and pathological changes modified by neutralization of TGF‐β were characterized in vivo. Nine and twelve days following infection, BALB/c mice were injected intraperitoneally with anti‐TGF‐β (1,2,3) antibodies, isotype control antibodies or isosmotic solution. We assessed both Th1 and Th2 related cytokines production ex vivo and in vitro, IgA, the number of CD4+ cells, and eosinophils in the lamina propria and the villus : crypt ratio in the small intestine 6 weeks after infection. The pattern of cytokine production differed in the intestine, peritoneal fluid and serum. In mice infected with H. polygyrus the concentrations of IL‐5, IL‐12, TNF‐α and IL‐10 were raised in the intestine, but in serum the level of cytokines was diminished below the value observed in uninfected mice. The neutralization of TGF‐β converted the pattern of immune response induced by H. polygyrus. The elevation of cytokines in serum coincided with the reduction of cytokine concentration in the intestine or peritoneum. Neutralization of TGF‐β restored infiltration of eosinophils into the lamina propria of the intestine despite the low level of IL‐5. We conclude that H. polygyrus infection suppresses the immune response through pathways involving TGF‐β production or activity and that the Th2 related immune response was not affected by neutralization.
Reporting vegetation condition using the Vegetation Assets, States and Transitions (VAST) framework
Authors: Thackway Richard , Lesslie Robert
Published: May 2006

Summary  The Vegetation Assets, States and Transitions (VAST) framework classifies vegetation by degree of human modification as a series of states, from intact native vegetation through to total removal. VAST is a simple communication and reporting tool designed to assist in describing and accounting for human‐induced modification of vegetation. A benchmark is identified for each vegetation association based on structure, composition and current regenerative capacity. Benchmarks are based on the best understanding of pre‐European conditions (sometimes called ‘fully natural’). Relative change in condition from this benchmark is assessed for each site or patch. Three case studies demonstrate use of the diagnostic criteria that underpin VAST. We argue that VAST has potential to provide a consistent framework for monitoring and reporting vegetation modification at a range of scales. Uses of VAST datasets for natural resource planning and management are discussed including a reporting and communication framework for describing the response of vegetation to changes in land use and land management practices, measuring progress toward vegetation targets and describing and mapping vegetation changes and trends.
Two‐stage U‐statistics for Hypothesis Testing
Authors: HO HWAI‐CHUNG , SHIEH GRACE S.
Published: May 2006

Abstract.  A U‐statistic is not easy to apply or cannot be applied in hypothesis testing when it is degenerate or has an indeterminate degeneracy under the null hypothesis. A class of two‐stage U‐statistics (TU‐statistics) is proposed to remedy these drawbacks. Both the asymptotic distributions under the null and the alternative of TU‐statistics are shown to have simple forms. When the degeneracy is indeterminate, the Pitman asymptotic relative efficiency of a TU‐statistic dominates that of the incomplete U‐statistics. If the kernel is degenerate under the null hypothesis but non‐degenerate under the alternative, a TU‐statistic is proved to be more powerful than its corresponding U‐statistic. Applications to testing independence of paired angles in ecology and marine biology are given. Finally, a simulation study shows that a TU‐statistic is more powerful than its corresponding incomplete U‐statistic in almost all cases under two settings.