bluuebunny/crossref_metadata_2025 huggingface dataset:
Impaired hyperphosphorylation of rotavirus NSP5 in cells depleted of casein kinase 1α is associated with the formation of viroplasms with altered morphology and a moderate decrease in virus replication
Authors: Campagna Michela , Budini Mauricio , Arnoldi Francesca , Desselberger Ulrich , Allende Jorge E. , Burrone Oscar R.
Published: September 2007

The rotavirus (RV) non-structural protein 5, NSP5, is encoded by the smallest of the 11 genomic segments and localizes in ‘viroplasms’, cytoplasmic inclusion bodies in which viral RNA replication and packaging take place. NSP5 is essential for the replicative cycle of the virus because, in its absence, viroplasms are not formed and viral RNA replication and transcription do not occur. NSP5 is produced early in infection and undergoes a complex hyperphosphorylation process, leading to the formation of proteins differing in electrophoretic mobility. The role of hyperphosphorylation of NSP5 in the replicative cycle of rotavirus is unknown. Previous in vitro studies have suggested that the cellular kinase CK1α is responsible for the NSP5 hyperphosphorylation process. Here it is shown, by means of specific RNA interference, that in vivo, CK1α is the enzyme that initiates phosphorylation of NSP5. Lack of NSP5 hyperphosphorylation affected neither its interaction with the virus VP1 and NSP2 proteins normally found in viroplasms, nor the production of viral proteins. In contrast, the morphology of viroplasms was altered markedly in cells in which CK1α was depleted and a moderate decrease in the production of double-stranded RNA and infectious virus was observed. These data show that CK1α is the kinase that phosphorylates NSP5 in virus-infected cells and contribute to further understanding of the role of NSP5 in RV infection.
Cytomegaloviral proteins pUL50 and pUL53 are associated with the nuclear lamina and interact with cellular protein kinase C
Authors: Milbradt Jens , Auerochs Sabrina , Marschall Manfred
Published: September 2007

Human cytomegalovirus-encoded pUL50 and pUL53 belong to a group of conserved herpesviral nuclear proteins. This study describes: (i) the co-localization of pUL50 with components of the nuclear lamina such as lamins A/C and lamin B receptor by double immunofluorescent staining, (ii) a strong pUL50-mediated relocalization of pUL53 from a diffuse nuclear pattern towards a nuclear rim localization, (iii) a direct interaction between pUL50 and pUL53, as well as between pUL50 and protein kinase C (PKC), shown by yeast two-hybrid and co-immunoprecipitation analyses, (iv) in vitro phosphorylation of pUL50, which is highly suggestive of PKC activity, and finally (v) partial relocalization of PKC by pUL50/pUL53 from its main cytoplasmic localization to a marked nuclear lamina accumulation. These data suggest a role for pUL50 and pUL53 in the recruitment of PKC, an event that is considered to be important for cytomegalovirus-induced distortion of the nuclear lamina.
A chimeric plum pox virus shows reduced spread and cannot compete with its parental wild-type viruses in a mixed infection
Authors: Dietrich Christof , Al Abdallah Qusai , Lintl Lara , Pietruszka Agnes , Maiss Edgar
Published: September 2007

The effect of a recombination event in the genomic 3′ end on the biological properties and competitiveness of plum pox virus (PPV) was investigated. Therefore, a fragment spanning the coat protein (CP) coding region and a part of the 3′ non-translated region of a non-aphid-transmissible strain of PPV (PPV-NAT) was replaced by the corresponding region of a PPV sour cherry isolate (PPV-SoC). The resulting chimera (PPV-NAT/SoC) caused severe symptoms inNicotiana benthamiana, resembling those of PPV-NAT. In mixed infections with either of the parental viruses, the chimera PPV-NAT/SoC was less competitive. Labelling experiments with DsRed showed that PPV-NAT/SoC (PPV-NAT/SoC-red) moved more slowly from cell to cell than PPV-NAT (PPV-NAT-red). In mixed infections of PPV-NAT/SoC-redwith a green fluorescent protein-expressing PPV-NAT (PPV-NAT-AgfpS), spatial separation of the viruses was observed. These data suggest that, in PPV infections, symptom severity and competitiveness are independent aspects and that spatial separation may contribute to the displacement of a recombinant virus.
Design of primers and use of RT-PCR assays for typing European bluetongue virus isolates: differentiation of field and vaccine strains
Authors: Mertens P. P. C. , Maan N. S. , Prasad G. , Samuel A. R. , Shaw A. E. , Potgieter A. C. , Anthony S. J. , Maan S.
Published: September 2007

Bluetongue virus (BTV) is the causative agent of bluetongue, a disease of ruminant livestock that occurs almost worldwide between latitudes 3 ° S and 5 ° N. There are 24 serotypes of BTV (currently identified by serum neutralization assays). Since 1998, eight strains of six BTV serotypes (1, 2, 4, 8, 9 and 16) have invaded Europe. The most variable BTV protein is major outer-capsid component VP2, encoded by segment 2 (Seg-2) of the double-stranded RNA virus genome. VP2 represents the major target for neutralizing (and protective) antibodies that are generated in response to BTV infection, and is therefore the primary determinant of virus serotype. RT-PCR primers and assays targeting Seg-2 have been developed for rapid identification (within 24 h) of the six European BTV types. These assays are sensitive, specific and show perfect agreement with the results of conventional virus-neutralization methods. Previous studies have identified sequence variations in individual BTV genome segments that allow different isolates to be grouped on the basis of their geographical origins (topotypes). The assays described in this paper can detect any of the BTV isolates of the homologous serotype that were tested from different geographical origins (different Seg-2 topotypes). Primers were also identified that could be used to distinguish members of these different Seg-2 topotypes, as well as field and vaccine strains of most of the European BTV serotypes. The serotype-specific assays (and primers) showed no cross-amplification when they were evaluated with multiple isolates of the most closely related BTV types or with reference strains of the remaining 24 serotypes. Primers developed in this study will be updated periodically to maintain their relevance to current BTV distribution and epidemiology (http://www.iah.bbsrc.ac.uk/dsRNA_virus_proteins/ReoID/rt-pcr-primers.htm).
Superinfection exclusion in BHK-21 cells persistently infected with Junín virus
Authors: Ellenberg Paula , Linero Florencia N. , Scolaro Luis A.
Published: September 2007

We characterized a persistently Junín virus (JUNV)-infected BHK-21 cell line obtained by experimental infection with the XJCl3 strain. This cell line, named K3, produced low levels of virus in supernatants which were not influenced by the presence of defective interfering (DI) particles after the first year of infection. K3 cells were able to exclude superinfection of the homologous JUNV and the antigenically related Tacaribe virus (TCRV), whereas the non-related arenaviruses lymphocytic choriomeningitis virus (LCMV) and Pichinde virus (PICV) could replicate normally. Although superinfecting virus binding and internalization to persistently infected cells were slightly reduced, earlier biosynthesis of antigenomic RNA was observed in comparison with BHK-21 cells. Despite the fact that superinfection did not increase the number of cells expressing viral antigens, de novo synthesis of superinfecting virus proteins was detected. The virus produced by JUNV-superinfected K3 cells remained mostly cell-associated in the form of particles tethered to the plasma membrane and aberrant tubular structures. JUNV restriction was correlated with an overexpression of cellular protein TSG101 in K3 cells, which has been pointed out as involved in the budding of several RNA viruses. This correlation was also observed in a cell clone isolated from K3. Reduction of TSG101 expression favoured the release of infectious virus to the supernatant of JUNV-superinfected K3 cells. Our data suggest that overexpression of TSG101 in K3 cells is a novel mechanism that may contribute, along with a diminished synthesis of superinfecting virus proteins, to explain superinfection exclusion in persistently arenavirus-infected cells.
Post-translational modifications of Epstein–Barr virus BARF1 oncogene-encoded polypeptide
Authors: de Turenne-Tessier Mireille , Ooka Tadamasa
Published: September 2007

Epstein–Barr virus is associated with several human lymphomas and carcinomas, and its BARF1 oncogene encodes a protein that is thought to play an important role in carcinogenesis. A BARF1 recombinant adenovirus expression system, which led us to discover the macromolecular size of the cleaved and secreted form of the BARF1 protein in the native state and its mitogenic capacity on various cell lines in culture, was used further to investigate the structure and maturation of the BARF1 protein. We recently reported biophysical studies that showed dimer-based oligomerization of the BARF1 polypeptide. Here, new data are presented that confirm post-translational modifications predicted from the BARF1 sequence: phosphorylation on serine and threonine, and N- and O-glycosylation. The N- and O-glycans were partially characterized and it was demonstrated that both modifications are required for active secretion of the BARF1 protein via the classical pathway.
Circular genomes related to anelloviruses identified in human and animal samples by using a combined rolling-circle amplification/sequence-independent single primer amplification approach
Authors: Biagini Philippe , Uch Rathviro , Belhouchet Mourad , Attoui Houssam , Cantaloube Jean-François , Brisbarre Nadège , de Micco Philippe
Published: September 2007

A combined rolling-circle amplification (RCA) and sequence-independent single primer amplification (SISPA) approach was applied to four samples of human plasma and one sample of saliva from a cat. This approach permitted the characterization of nine anelloviruses. Most of them were identified as highly divergent strains that were classified into species of the genusAnellovirus. The smallest anellovirus described so far in humans was characterized (2PoSMA, 2002 nt; ‘small anellovirus’ species). Two highly divergent sequences belonging to the speciesTorque Teno Mini Virus(LIL-y1, 2887 nt; LIL-y2, 2871 nt), which clustered into a new phylogenetic branch, were also identified in human plasma samples. Finally, two genomes that are separated by a genetic divergence of 46 % were characterized in the cat's saliva, one of these creating a distinct phylogenetic branch (PRA1, 2019 nt). These results highlight the potential of RCA–SISPA for detecting circular (or circularized) genomes.
Biological properties and relative fitness of inter-subgroup cucumber mosaic virus RNA 3 recombinants produced in vitro
Authors: Pierrugues Olivier , Guilbaud Laurent , Fernandez-Delmond Isabelle , Fabre Frédéric , Tepfer Mark , Jacquemond Mireille
Published: September 2007

In vitro reverse transcription of a mixture of total RNA from plants infected with the I17F or R strains of cucumber mosaic virus (CMV), representative of subgroups IA and II, respectively, results in viral cDNA populations including rare recombinant RNA 3 molecules, some of which also have point mutations. The biological properties of 17 recombinants in the capsid gene or the 3′ non-coding region of RNA 3 were evaluated when associated with I17F RNAs 1 and 2. Six viruses displayed deficiencies (non-viability, deficiencies for movement and/or replication, delayed infection, loss of aphid transmissibility). Nine induced symptoms close to those of I17F-CMV on tobacco and pepper plants. All recombinants bearing the movement protein (MP) of R-CMV and part or most of the capsid protein (CP) of I17F-CMV, as well as the recombinant created in vitro by exchanging the corresponding open reading frames, also induced filiformism on tobacco, but induced only faint symptoms on melon. Two recombinants induced atypically severe symptoms on both tobacco and pepper. Most of the recombinants generally accumulated to lower levels than the wild-type I17F strain in tobacco. Three recombinants, however, including one responsible for severe symptoms, accumulated to generally higher levels than I17F-CMV. When two of these were tested in co-infection experiments with I17F RNA 3, they proved to be poorly competitive, suggesting that they would be unlikely to emerge in the field.
Immunization of Syrian golden hamsters with F subunit vaccine of human metapneumovirus induces protection against challenge with homologous or heterologous strains
Authors: Herfst Sander , de Graaf Miranda , Schrauwen Eefje J. A. , Ulbrandt Nancy D. , Barnes Arnita S. , Senthil Kannaki , Osterhaus Albert D. M. E. , Fouchier Ron A. M. , van den Hoogen Bernadette G.
Published: September 2007

Human metapneumovirus (hMPV), a newly discovered paramyxovirus, is associated with acute respiratory-tract illness, primarily in young children, individuals with underlying disease and the elderly. Two genetic lineages of hMPV circulate around the world, and viruses from these two lineages demonstrate antigenic differences. The clinical impact of hMPV warrants the development of vaccines. Recombinant soluble fusion (F) proteins of prototype viruses of the two main lineages of hMPV that can be produced in high yields have been constructed. In this study, the antigenicity, immunogenicity and protective efficacy of these soluble F subunit vaccines were evaluated in Syrian golden hamsters (Mesocricetus auratus). Immunization of hamsters with the soluble F proteins, adjuvanted with Specol or iscom matrix, induced high virus-neutralization titres, with higher titres against the homologous than the heterologous virus. The neutralizing antibodies protected from subsequent infection of the lungs with both homologous and heterologous virus. Upon challenge, viral titres in the nasal turbinates of immunized animals were reduced significantly compared with those of PBS-immunized animals. In conclusion, a soluble F subunit vaccine for hMPV that induces cross-protective immunity for infection of the lower respiratory tract in Syrian golden hamsters has been generated.
Maternofetal transmission of hepatitis B virus genotype E in Ghana, west Africa
Authors: Candotti Daniel , Danso Kwabena , Allain Jean-Pierre
Published: September 2007

To determine whether maternofetal transmission of hepatitis B virus (HBV) is a common route of infection leading to chronic infection in west Africa, plasma samples, obtained at delivery from 1368 pregnant Ghanaian women and paired umbilical cord blood or newborn whole blood samples, were tested for HBV surface antigen (HBsAg) and DNA. A 16 % prevalence of HBV chronic carriers, defined as detectable HBsAg and/or HBV DNA, was found, >80 % contained less than 1×104 IU ml−1 HBV DNA and 99 % were infected with genotype E strains. HBV maternofetal transmission was documented in 17 out of 204 (8.3 %) paired HBV carrier women–cord blood/newborn samples. The rate of transmission was 55 % and 3.3 % when maternal viral load was above or below 1×104 IU ml−1, respectively (P=0.0008). Maternofetal transmission of HBV genotype E was estimated to account for 8 % of the cases of chronic HBsAg carriers. Six women with low viral load at delivery (five <20 IU ml−1) and anti-HBe (hepatitis B e antigen) transmitted HBV. Surprisingly, while non-transmitted low viral load strains had 79 % mutations at position 1896 of HBV genome, transmitted strains were all wild-type despite anti-HBe presence (P=0.0041), suggesting the possible role of HBeAg as risk factor for HBV maternofetal transmission. The relative risk of maternofetal transmission was 2.4 when pregnant women carried high viral load and 11.5 when carrying wild-type strains at position 1896, irrespective of viral load. We conclude that viral load and pre-core wild-type at position 1896 are two independent risk factors for HBV genotype E maternofetal transmission, which remains a minor contributor to high prevalence of chronic infection.
Dicer is involved in protection against influenza A virus infection
Authors: Matskevich Alexey A. , Moelling Karin
Published: September 2007

In mammals the interferon (IFN) system is a central innate antiviral defence mechanism, while the involvement of RNA interference (RNAi) in antiviral response against RNA viruses is uncertain. Here, we tested whether RNAi is involved in the antiviral response in mammalian cells. To investigate the role of RNAi in influenza A virus-infected cells in the absence of IFN, we used Vero cells that lack IFN-αand IFN-βgenes. Our results demonstrate that knockdown of a key RNAi component, Dicer, led to a modest increase of virus production and accelerated apoptosis of influenza A virus-infected cells. These effects were much weaker in the presence of IFN. The results also show that in both Vero cells and the IFN-producing alveolar epithelial A549 cell line influenza A virus targets Dicer at mRNA and protein levels. Thus, RNAi is involved in antiviral response, and Dicer is important for protection against influenza A virus infection.
Ectropis obliqua picorna-like virus IRES-driven internal initiation of translation in cell systems derived from different origins
Authors: Lu Jie , Hu Yuanyang , Hu Liu , Zong Shan , Cai Dawei , Wang Junping , Yu Haiyang , Zhang Jiamin
Published: September 2007

Ectropis obliquapicorna-like virus (EoPV) is an insect RNA virus that causes a lethal granulosis infection of larvae of the tea looper (Ectropis obliqua). An internal ribosome entry site (IRES) mediates translation initiation of EoPV RNA. Here, bicistronic constructs were used to examine the 5′ untranslated region (UTR) of EoPV for IRES activity. The capacities of the EoPV 5′ UTR IRES and another insect virus IRES, the cricket paralysis virus intergenic region IRES, to mediate internal translation initiation in a variety of translation systems were also compared. The results demonstrated that the EoPV IRES functioned efficiently not only in mammalian cell-derived systems, but also in an insect cell-derived translation system. However, it functioned inefficiently in a plant cell-derived translation system. This study reveals the host preferences of the EoPV IRES and important differences in IRES function between the EoPV IRES and other characterized picorna-like insect viral IRESs.
Requirement of JIP scaffold proteins for NMDA-mediated signal transduction
Authors: Kennedy Norman J. , Martin Gilles , Ehrhardt Anka G. , Cavanagh-Kyros Julie , Kuan Chia-Yi , Rakic Pasko , Flavell Richard A. , Treistman Steven N. , Davis Roger J.
Published: September 2007

JIP scaffold proteins are implicated in the regulation of protein kinase signal transduction pathways. To test the physiological role of these scaffold proteins, we examined the phenotype of compound mutant mice that lack expression of JIP proteins. These mice were found to exhibit severe defects in N-methyl-D-aspartic acid (NMDA) receptor function, including decreased NMDA-evoked current amplitude, cytoplasmic Ca++, and gene expression. The decreased NMDA receptor activity in JIP-deficient neurons is associated with reduced tyrosine phosphorylation of NR2 subunits of the NMDA receptor. JIP complexes interact with the SH2 domain of cFyn and may therefore promote tyrosine phosphorylation and activity of the NMDA receptor. We conclude that JIP scaffold proteins are critically required for normal NMDA receptor function.
Structure of RbFeO2, refined from a reticular pseudomerohedrally twinned crystal with six domains
Authors: Nuss Jürgen , Ali Naveed Zafar , Jansen Martin
Published: September 2007

RbFeO2, rubidium oxoferrate, crystallizes as an orthorhombic structure. The crystals under investigation were composed of six individuals representing reticular pseudomerohedral twins with a pseudocubic twin lattice of index 4 because of the approximate equations a(8)1/2 = b(2)1/2 = c. The compound is isostructural with KFeO2 (KGaO2 type of structure) and is composed of [FeO4/2]– corner-sharing tetrahedra, forming a three-dimensional cristobalite-like network, with Rb+ ions occupying its interstices.
Modes of cytometric bacterial DNA pattern: a tool for pursuing growth
Authors: Müller S.
Published: September 2007

Abstract.  Analyses of DNA pattern provide an excellent tool to determine activity states of bacteria. Bacterial cell cycle behaviour is generally different from the eukaryotic one and is pre‐determined by the bacteria's diversity within the phylogenetic tree, and their metabolic traits. As a result, every species creates its specific proliferation pattern that differs from every other one. Up to now, just few bacterial species have been investigated and little information is available concerning DNA cycling even in already known species. This prevents understanding of the complexity and diversity of ongoing bacterial interactions in many ecosystems or in biotechnology. Flow cytometry is the only possible technique to shed light on the dynamics of bacterial communities and DNA patterns will help to unlock the hidden principles of their life. This review provides basic knowledge about the molecular background of bacterial cell cycling, discusses modes of cell cycle phases and presents techniques to both obtain DNA patterns and to combine the contained information with physiological cell states.
Antiproliferative and apoptotic effects in rat and human hepatoma cell cultures of the orally active iron chelator ICL670 compared to CP20: a possible relationship with polyamine metabolism
Authors: Lescoat G. , Chantrel‐Groussard K. , Pasdeloup N. , Nick H. , Brissot P. , Gaboriau F.
Published: September 2007

Abstract.  Objective: Iron loading has been observed to have a hyperproliferative effect on hepatocytes in vitro and on tumour cells in vivo; removal of this iron being required to induce antitumour activity. Material and Methods: Antiproliferative effects of orally active tridentate iron chelator ICL670 (deferasirox) and bidentate iron chelator CP20 (deferiprone), mediated through the chelation of intracellular iron, were compared in rat hepatoma cell line FAO and human hepatoma cell line HUH7. Results: In FAO cell cultures, we have shown that ICL670 decreased cell viability and DNA replication and induced apoptosis more efficiently than an iron‐binding equivalent concentration of CP20. Moreover, ICL670 decreased significantly the number of the cells in G2‐M phase. In the HUH7 cell cultures, ICL670 and a four‐time higher iron‐binding equivalent concentration of CP20, decreased cell viability and DNA replication in the same range. CP20 increased the number of the cells in G2‐M phase. However, ICL670 inhibited polyamine biosynthesis by decreasing ornithine decarboxylase mRNA level; in contrast, CP20 increased polyamine biosynthesis, particularly putrescine level, by stimulating spermidine‐spermine N1‐acetyl transferase activity that could activate the polyamine retro‐conversion pathway. By mass spectrometry, we observed that ICL670 cellular uptake was six times higher than CP20. Conclusions: These results suggest that ICL670 has a powerful antitumoural effect and blocks cell proliferation in neoplastic cells by a pathway different from that of CP20 and may constitute a potential adjuvant drug for anticancer therapy.
Effect of growth hormone deficiency and recombinant hGH (rhGH) replacement on the hypothalamic–pituitary–adrenal axis in children with idiopathic isolated GH deficiency
Authors: Giavoli Claudia , Bergamaschi Silvia , Ferrante Emanuele , Ronchi Cristina L. , Lania Andrea G. , Rusconi Roberto , Spada Anna , Beck‐Peccoz Paolo
Published: September 2007

Objective  Recombinant hGH (rhGH) therapy may unmask central hypoadrenalism in adults with organic GH deficiency (GHD), likely by normalizing 11β‐hydroxysteroid dehydrogenase type 1 isoenzyme (11βHSD1) activity and reducing cortisone to cortisol conversion. The aim of the present study was to evaluate the hypothalamic–pituitary–adrenal (HPA) axis in children with idiopathic isolated GHD and normal pituitary magnetic resonance imaging (MRI) both before and during rhGH therapy.

Design and patients  This was a single‐centre study of 10 consecutive children [five males and five females, mean age: 12·2 ± 1·0 year]. Evaluation was performed at baseline and on rhGH (mean duration: 10·9 ± 2·9 months, mean dose: 0·030 ± 0·002 mg/kg bw/day).

Measurements  HPA function was assessed by serum cortisol levels before and after appropriate provocative stimuli, that is, 1 µg ACTH test (N = 5 patients) or insulin tolerance test (ITT, N = 5 patients), evaluating all children with the same stimulation test both before and during rhGH therapy. Central hypoadrenalism was excluded by the presence of either a peak of > 500 nmol/l or a rise in cortisol levels of > 200 nmol/l, after both tests.

Results  On rhGH therapy, serum IGF‐I levels normalized, while serum cortisol and ACTH levels did not significantly differ from those recorded at baseline. The mean serum cortisol peak after both provocative tests was not significantly different on rhGH therapy and at baseline (498 ± 41 vs. 580 ± 35 nmol/l, respectively, P = 0·06), the mean cortisol rise being 280 ± 45 and 270 ± 36 nmol/l on rhGH and at baseline, respectively.

Conclusions  According to the diagnostic criteria, no child became hypoadrenal on rhGH, contrary to what observed in patients with organic GHD, further supporting the view that only in patients with organic multiple pituitary hormone deficiency GHD masks the presence of a hidden central hypoadrenalism.
Effects of ultraviolet radiation on litter decomposition depend on precipitation and litter chemistry in a shortgrass steppe ecosystem
Authors: BRANDT LESLIE A. , KING JENNIFER Y. , MILCHUNAS DANIEL G.
Published: September 2007

We examined the effect of altered levels of ultraviolet (UV) radiation (280–400 nm) and different amounts of precipitation on the decomposition rates of litter of contrasting carbon to nitrogen ratio (C : N) in a 3‐year field experiment in a shortgrass steppe (SGS) ecosystem. UV radiation was either blocked or passed under clear plastic tents where precipitation was applied to simulate a very dry or very wet year. These treatments minimized or maximized the abiotic component (UV) or the biotic component (biological activity of decomposer organisms) of decomposition to assess potential interactions between the two. Initial litter chemistry varied in response to having been grown under ambient or elevated atmospheric CO2concentrations. While precipitation and litter chemistry were the most important drivers in decomposition in this system, UV radiation increased decomposition rates under dry conditions in litter with higher C : N ratios. Exposure to UV radiation slightly increased the amount of holocellulose that was lost from the litter. UV exposure did not affect the decomposition of the lignin fraction. Increased decomposition with UV radiation was accompanied by a decrease in N immobilization over the summer months. These results suggest that the effects of UV radiation on decomposition rates may be primarily abiotic, caused by direct photochemical degradation of the litter. Our results demonstrate that the role of UV radiation in litter decomposition in semiarid systems depends on the aridity of the system and the chemistry of the litter.
Variation in the δ13C of foliage of Pinus sylvestris L. in relation to climate and additions of nitrogen: analysis of a 32‐year chronology
Authors: BETSON NICHOLAS R. , JOHANNISSON CHRISTIAN , LÖFVENIUS MIKAELL OTTOSSON , GRIP HARALD , GRANSTRÖM ANDERS , HÖGBERG PETER
Published: September 2007

We report an analysis of both the long‐ and short‐term drivers of the carbon (C) isotope composition (δ13C) values of current year needles of Pinus sylvestris L. linked to changing atmospheric carbon dioxide (CO2) concentrations (ca) and climate using data from a uniquely long‐term nitrogen (N) fertilization experiment in the north of Sweden (consisting of three N dosage levels and a control treatment) from 1970 until 2002. N loading produced trees with less negative δ13C of foliage, by around 0.45‰ on average, with the difference in δ13C between control and N treatments not dependant upon N dosage. The average δ13C values decreased at a rate of around 0.03‰ yr−1, even after accounting for the Suess effect (the decrease in the atmospheric CO2δ13C due to anthropogenic emissions of isotopically light CO2). This decrease is large enough to cause a significant, progressive change in the δ13C down through a soil profile. Modelled values of plant intrinsic water use efficiency (WUEi) and the ratio of leaf internal to external [CO2] (ci/ca) showed that this was the result of ci increasing in parallel with ca (while ci/ca increased), thus causing little change in WUEi over the 32 years of study. The residuals from the relationships between year and δ13C were used to examine the impact of climate on the interannual variation of C isotope composition of needles. This included the use of a fire hazard index (FHI) model, which integrates climatic factors known to influence plant stomatal conductance and hence δ13C. The FHI produced the best fit with δ13C values when climate data were averaged over the whole growth season (for control plots) and for July for all the N treatments, explaining ca. 60% of the total interannual variation in δ13C. Further, trees from the N treatments appeared more susceptible to air‐humidity‐based climate parameters, as seen from higher correlation coefficients, than were control trees. Thus, our data suggest the possibility of increased susceptibility to drought conditions in ecosystems with moderate to high N deposition rates. Also, there is the possibility that, because there was no apparent change in WUEi of P. sylvestris in this ecosystem over the last 32 years, the rate of sequestration of C into boreal ecosystems may not increase with ca, as has been predicted.
Nurses’ views on the use, quality and user satisfaction with electronic medical records: questionnaire development
Authors: Otieno Ochieng George , Toyama Hinako , Asonuma Motohiro , Kanai‐Pak Masako , Naitoh Keiko
Published: September 2007

Title. Nurses’ views on the use, quality and user satisfaction with electronic medical records: questionnaire development

Aim.  This paper is a report of the development of an instrument to measure nurses’ views on the use, quality and user satisfaction with electronic medical records systems.

Background.  Use of electronic medical records systems in hospitals is steadily increasing, yet no validated instruments have assessed the effectiveness of these systems from the viewpoint of nurses.

Method.  Items were designed following a literature review based on three main constructs: use, quality and user satisfaction with electronic medical records. Reliability and validity were examined based on responses from 1666 nurses from 42 hospitals in Japan in February 2006. Exploratory factor analysis was conducted to determine the degree to which each item within a construct was associated. The reliability of each resultant factor was computed using Cronbach’s alpha coefficient. Content validity was addressed by basing the items on previous surveys and review of the instrument by a panel of nurses experienced in nursing informatics. Construct validity was examined through factor analysis and correlational analyses.

Findings.  Extent of ‘use’ of electronic medical records resulted into three factors with good factor loadings, but only two had acceptable reliability. ‘Quality’ of electronic medical records had two factors with good factor loadings and reliability. ‘User satisfaction’ with electronic medical records had three factors, but only one had acceptable reliability. ‘Use’ and ‘quality’ constructs were positively correlated with ‘user satisfaction’.

Conclusion.  The final instrument incorporates 34 items from the original 44‐item pool. Initial validity results were positive and therefore the instrument can be used in evaluating electronic medical records in hospitals.
Standard medication information is not enough: poor concordance of patient and nurse perceptions
Authors: Ekman Inger , Schaufelberger Maria , Kjellgren Karin I. , Swedberg Karl , Granger Bradi B.
Published: September 2007

Title. Standard medication information is not enough: poor concordance of patient and nurse perceptions

Aim.  This paper is a report of a study to describe patient and nurse perceptions of patient satisfaction with information about the medicines at two heart failure clinics after medication up‐titration and information‐giving.

Background.  Chronic heart failure is a major cause of hospitalization. Poor adherence to medications increases mortality and heart failure‐related hospitalizations. To achieve mutual goal‐setting (concordance) regarding medication‐taking behaviours, health providers need to understand patient information needs regarding the prescribed medicines.

Methods.  A convenience sample of 56 patients with chronic heart failure referred for an up‐titration of medicines and information‐giving about the condition and treatment completed the Satisfaction about Information about Medicines Scale at their first and last visits. Nurses completed the same questionnaire after each patient’s final visit, assessing the patient’s need for further information. The data were collected between 2002 and 2004.

Results.  Patient scores indicated statistically significantly more satisfaction with their information at the final visit compared with the first visit (P = 0·005). However, at the programme conclusion, nurses (n = 7) rated patients to be appropriately informed while patients reported a persistent need for further information (P = 0·011).

Conclusion.  Further research should evaluate more advanced pedagogical strategies such as how to address patients’ expectations about the effect of medicines when actual effects of the treatment are related to mortality and morbidity at the population level and may not result directly in symptom relief at an individual level.
Importance of illness beliefs and self‐efficacy for patients with coronary heart disease
Authors: Lau‐Walker Margaret
Published: September 2007

Title. Importance of illness beliefs and self‐efficacy for patients with coronary heart disease

Aim.  This paper is a report of a study to assess the association between coronary heart disease patients’ illness beliefs and their self‐efficacy 3 years after hospital discharge.

Background.  Cardiac rehabilitation guidelines recommend that both the illness representation model and the concept of self‐efficacy are relevant frameworks for developing effective psychological support, although little is known about what aspects of patients' illness beliefs influence their self‐efficacy.

Method.  In a longitudinal prospective survey, consecutive patients with coronary heart disease were asked to complete questionnaires measuring illness perceptions; self‐efficacy and demographic, illness characteristics; and attendance at a cardiac rehabilitation programme. The questionnaire was completed three times between 2001 and 2005. The response rates were 84% at time 1, 77% at time 2 and 72% at time 3. Multiple regression analysis was used to assess the association between illness beliefs and self‐efficacy. The data were collected between 2001 and 2005.

Findings.  The average age of the participants was 65 years, 79% were male, 50% had acute myocardial infarction, 50% had angina and 61% had no previous history of cardiac illness; 55% had been admitted as an emergency and 57% subsequently attended cardiac rehabilitation. At baseline 30% of the variance in the exercise self‐efficacy at 3 years after index admission was accounted for by patients’ view of their illness being long‐term. Data collected 9 months after discharge showed similar findings.

Conclusion.  Early interventions designed to address individuals’ sense of control, beliefs about the length of illness and the management of perceived symptoms before hospital discharge could increase rehabilitation programmes effectiveness in sustaining patients’ long‐term lifestyle changes.
Technology‐assisted learning: a longitudinal field study of knowledge category, learning effectiveness and satisfaction in language learning
Authors: Hui W. , Hu P.J.‐H. , Clark T.H.K. , Tam K.Y. , Milton J.
Published: September 2007

Abstract  A field experiment compares the effectiveness and satisfaction associated with technology‐assisted learning with that of face‐to‐face learning. The empirical evidence suggests that technology‐assisted learning effectiveness depends on the target knowledge category. Building on Kolb's experiential learning model, we show that technology‐assisted learning improves students' acquisition of knowledge that demands abstract conceptualization and reflective observation but adversely affects their ability to obtain knowledge that requires concrete experience. Technology‐assisted learning better supports vocabulary learning than face‐to‐face learning but is comparatively less effective in developing listening comprehension skills. In addition, according to empirical tests, perceived ease of learning and learning community support significantly predict both perceived learning effectiveness and learning satisfaction. Overall, the results support our hypotheses and research model and suggest instructors should consider the target knowledge when considering technology‐assisted learning options or designing a Web‐based course. In addition, a supportive learning community can make technology‐assisted learning easier for students and increase their learning satisfaction.
Motivational beliefs and perceptions of instructional quality: predicting satisfaction with online training*
Authors: Artino A.R.
Published: September 2007

Abstract Many would agree that learning on the Web – a highly autonomous learning environment – may be difficult for individuals who lack motivation and self‐regulated learning skills. Using a social cognitive view of academic motivation and self‐regulation, the objective of the present study was to investigate the relations between students' motivational beliefs, their perceptions of the learning environment and their satisfaction with a self‐paced, online course. Service academy undergraduates (n = 646) completed a questionnaire following online training. Pearson correlations indicate that task value, self‐efficacy and perceived instructional quality were significantly positively related to each other and to students' overall satisfaction with the self‐paced, online course. Additionally, results from a three‐step hierarchical regression reveal that task value, self‐efficacy and instructional quality were significant positive predictors of students' satisfaction; the final regression model accounted for approximately 54% of the variance in the outcome measure. These findings support and extend prior research in traditional classrooms and online education in university settings, indicating that military students' motivational beliefs about a learning task and their perceptions of instructional quality are related, in important ways, to their overall satisfaction with online instruction. Educational implications and suggestions for future research are discussed.
Heterogeneity within the native range: population genetic analyses of sympatric invasive and noninvasive clades of the freshwater invading copepodEurytemora affinis
Authors: WINKLER GESCHE , DODSON JULIAN J. , LEE CAROL EUNMI
Published: September 2007

Invasive species are often composed of highly differentiated populations or sibling species distributed across their native ranges. This study analysed patterns of distribution and the evolutionary and demographic histories of populations within the native range of the copepod species complexEurytemora affinis. Genetic structure was analysed for samples from 17 locations from both the invaded and native ranges in the St Lawrence River drainage basin, using 652 base pairs of the mitochondrial cytochrome oxidase subunit I gene. This study revealed a high degree of heterogeneity in genetic structure and habitat type in the native range, as well as a bias in the sources of invasive populations. Two genetically distinct clades showed a pattern of niche partitioning within the St Lawrence basin. The noninvasive North Atlantic clade primarily occupied the central portion of the St Lawrence Middle Estuary, whereas the invasive Atlantic clade was more prevalent along the margins, in the upstream reaches of the estuary and downstream salt marshes. Habitat partitioning and genetic subdivision was also present within the Atlantic clade. The freshwater populations were genetically more proximate to the Atlantic clade populations in the estuary than to those in the salt marsh, suggesting the estuary as the source of the invasive populations. The freshwater invading populations showed evidence of a modest population bottleneck. Populations from both clades showed genetic signatures of demographic population expansions that preceded the timing of the last glacial maximum, supporting the St Lawrence as a secondary contact zone between the two clades. Additional analyses on physiological and evolutionary properties of populations in the native range, along with analysis of the selection regime within native habitats, might yield insights into the evolutionary potential to invade.
Multi‐locus DNA sequence data reveal a history of deep cryptic vicariance and habitat‐driven convergence in the desert night lizard Xantusia vigilis species complex (Squamata: Xantusiidae)
Authors: LEAVITT DEAN H. , BEZY ROBERT L. , CRANDALL KEITH A. , SITES JR JACK W.
Published: September 2007

The lizard genus Xantusia of southwestern North America has received recent attention in relation to delimiting species. Using more than 500 lizards from 156 localities, we further test hypothesized species boundaries and clarify phylogeographical patterns, particularly in regions of potential secondary contact. We sequenced the entire mitochondrial cytochrome b gene for every lizard in the study, plus a second mitochondrial DNA (mtDNA) region and two nuclear introns for subsets of the total sample. Phylogenetic analyses of the mtDNA recover a well‐resolved, novel hypothesis for species in the Xantusia vigilis complex. The nuclear DNA (nDNA) data provide independent support for the recognition of X. arizonae, X. bezyi and X. wigginsi. Differences between the respective mtDNA and nDNA topologies result from either the effects of lineage sorting or ancient introgression. Nuclear data confirm the inference that some populations of X. vigilis in northwestern Arizona converged on rock‐crevice‐dwelling morphology and are not X. arizonae with an introgressed X. vigilis mtDNA genome. The historical independence of ancient cryptic lineages of Xantusia in southern California is also corroborated, though limited introgression is detected. Our proposed biogeographical scenario indicates that diversification of this group was driven by vicariance beginning in the late Miocene. Additionally, Pleistocene climatical changes influenced Xantusia distribution, and the now inhospitable Colorado Desert previously supported night lizard presence. The current taxonomy of the group likely underestimates species diversity within the group, and our results collectively show that while convergence on the rock‐crevice‐dwelling morphology is one hallmark of Xantusia evolution, morphological stasis is paradoxically another.
Conserving the evolutionary potential of California valley oak (Quercus lobata Née): a multivariate genetic approach to conservation planning
Authors: GRIVET DELPHINE , SORK VICTORIA L. , WESTFALL ROBERT D. , DAVIS FRANK W.
Published: September 2007

California valley oak (Quercus lobata Née) is a seriously threatened endemic oak species in California and a keystone species for foothill oak ecosystems. Urban and agricultural development affects a significant fraction of the species’ range and predicted climate change is likely to dislocate many current populations. Here, we explore spatial patterns of multivariate genotypes and genetic diversity throughout the range of valley oak to determine whether ongoing and future patterns of habitat loss could threaten the evolutionary potential of the species by eradicating populations of distinctive genetic composition. This manuscript will address three specific questions: (i) What is the spatial genetic structure of the chloroplast and nuclear genetic markers? (ii) What are the geographical trends in the distribution of chloroplast and nuclear genotypes? (iii) Is there any part of the species’ range where allelic diversity in either the chloroplast or nuclear genomes is particularly high? We analysed six chloroplast and seven nuclear microsatellite genetic markers of individuals widespread across the valley oak range. We then used a multivariate approach correlating genetic markers and geographical variables through a canonical trend surface analysis, followed by GIS mapping of the significant axes. We visualized population allelic richness spatially with GIS tools to identify regions of high diversity. Our findings, based on the distribution of multivariate genotypes and allelic richness, identify areas with distinctive histories and genetic composition that should be given priority in reserve network design, especially because these areas also overlap with landscape change and little degree of protection. Thus, without a careful preservation plan, valuable evolutionary information will be lost for valley oak.
Sea ice occurrence predicts genetic isolation in the Arctic fox
Authors: GEFFEN ELI , WAIDYARATNE SITARA , DALÉN LOVE , ANGERBJÖRN ANDERS , VILA CARLES , HERSTEINSSON PALL , FUGLEI EVA , WHITE PAULA A. , GOLTSMAN MICHAEL , KAPEL CHRISTIAN M. O. , WAYNE ROBERT K.
Published: September 2007

Unlike Oceanic islands, the islands of the Arctic Sea are not completely isolated from migration by terrestrial vertebrates. The pack ice connects many Arctic Sea islands to the mainland during winter months. The Arctic fox (Alopex lagopus), which has a circumpolar distribution, populates numerous islands in the Arctic Sea. In this study, we used genetic data from 20 different populations, spanning the entire distribution of the Arctic fox, to identify barriers to dispersal. Specifically, we considered geographical distance, occurrence of sea ice, winter temperature, ecotype, and the presence of red fox and polar bear as nonexclusive factors that influence the dispersal behaviour of individuals. Using distance‐based redundancy analysis and the BIOENV procedure, we showed that occurrence of sea ice is the key predictor and explained 40–60% of the genetic distance among populations. In addition, our analysis identified the Commander and Pribilof Islands Arctic populations as genetically unique suggesting they deserve special attention from a conservation perspective.