bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced broadband near-infrared luminescence in transparent silicate glass ceramics containing Yb3+ ions and Ni2+-doped LiGa5O8 nanocrystals
Authors: Wu Botao , Ruan Jian , Ren Jinjun , Chen Danping , Zhu Congshan , Zhou Shifeng , Qiu Jianrong
Published: January 2008

Spectral properties of Yb3+∕Ni2+ codoped transparent silicate glass ceramics containing LiGa5O8 nanocrystals were investigated. The near-infrared emission intensity of Ni2+ was largely increased with Yb3+ codoping due to Yb3+→Ni2+ energy transfer. The qualitative calculation of the energy transfer constant Cs-a and rate Ps-a showed that the Yb3+→Ni2+ energy transfer was much greater than in the opposite direction. Yb3+∕Ni2+ codoped glass ceramics with 0.75mol% Yb2O3 exhibited a near-infrared emission with full width at half maximum of 290nm and fluorescent lifetime of 920μs. The glass ceramics are promising for broadband optical amplification.
Transport properties of branched graphene nanoribbons
Authors: Andriotis Antonis N. , Menon Madhu
Published: January 2008

The electronic transport properties of three-terminal graphene nanoribbon T-junctions are investigated using a quantum tight binding molecular dynamics scheme. The transport properties are found to depend very sensitively on the geometric features of the branches of the junctions. This dependence is even more pronounced than the corresponding dependence in the case of T-shaped single wall carbon nanotubes. This is attributed to the strong dependence of the conductivity of the nanoribbons on their chirality, width, and length. An additional factor that influences the conductivity of the T-junction nanoribbons is associated with the junction itself, i.e., the way the branches are interconnected.
Risk of natural disturbances makes future contribution of Canada's forests to the global carbon cycle highly uncertain
Authors: Kurz Werner A. , Stinson Graham , Rampley Gregory J. , Dymond Caren C. , Neilson Eric T.
Published: January 2008

A large carbon sink in northern land surfaces inferred from global carbon cycle inversion models led to concerns during Kyoto Protocol negotiations that countries might be able to avoid efforts to reduce fossil fuel emissions by claiming large sinks in their managed forests. The greenhouse gas balance of Canada's managed forest is strongly affected by naturally occurring fire with high interannual variability in the area burned and by cyclical insect outbreaks. Taking these stochastic future disturbances into account, we used the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to project that the managed forests of Canada could be a source of between 30 and 245 Mt CO
2
e yr
−1
during the first Kyoto Protocol commitment period (2008–2012). The recent transition from sink to source is the result of large insect outbreaks. The wide range in the predicted greenhouse gas balance (215 Mt CO
2
e yr
−1
) is equivalent to nearly 30% of Canada's emissions in 2005. The increasing impact of natural disturbances, the two major insect outbreaks, and the Kyoto Protocol accounting rules all contributed to Canada's decision not to elect forest management. In Canada, future efforts to influence the carbon balance through forest management could be overwhelmed by natural disturbances. Similar circumstances may arise elsewhere if global change increases natural disturbance rates. Future climate mitigation agreements that do not account for and protect against the impacts of natural disturbances, for example, by accounting for forest management benefits relative to baselines, will fail to encourage changes in forest management aimed at mitigating climate change.
Mutations in
NALP12
cause hereditary periodic fever syndromes
Authors: Jéru I. , Duquesnoy P. , Fernandes-Alnemri T. , Cochet E. , Yu J. W. , Lackmy-Port-Lis M. , Grimprel E. , Landman-Parker J. , Hentgen V. , Marlin S. , McElreavey K. , Sarkisian T. , Grateau G. , Alnemri E. S. , Amselem S.
Published: January 2008

NALP proteins, also known as NLRPs, belong to the CATERPILLER protein family involved, like Toll-like receptors, in the recognition of microbial molecules and the subsequent activation of inflammatory and immune responses. Current advances in the function of NALPs support the recently proposed model of a disease continuum bridging autoimmune and autoinflammatory disorders. Among these diseases, hereditary periodic fevers (HPFs) are Mendelian disorders associated with sequence variations in very few genes; these variations are mostly missense mutations whose deleterious effect, which is particularly difficult to assess, is often questionable. The growing number of identified sporadic cases of periodic fever syndrome, together with the lack of discriminatory clinical criteria, has greatly hampered the identification of new disease-causing genes, a step that is, however, essential for appropriate management of these disorders. Using a candidate gene approach, we identified nonambiguous mutations in
NALP12
(i.e., nonsense and splice site) in two families with periodic fever syndromes. As shown by means of functional studies, these two
NALP12
mutations have a deleterious effect on NF-κB signaling. Overall, these data identify a group of HPFs defined by molecular defects in
NALP12
, opening up new ways to manage these disorders. The identification of these first
NALP12
mutations in patients with autoinflammatory disorder also clearly demonstrates the crucial role of NALP12 in inflammatory signaling pathways, thereby assigning a precise function to this particular member of an emerging family of proteins whose putative biological properties are currently inferred essentially through
in vitro
means.
High-resolution structures of HIV-1 reverse transcriptase/TMC278 complexes: Strategic flexibility explains potency against resistance mutations
Authors: Das Kalyan , Bauman Joseph D. , Clark Arthur D. , Frenkel Yulia V. , Lewi Paul J. , Shatkin Aaron J. , Hughes Stephen H. , Arnold Eddy
Published: January 2008

TMC278 is a diarylpyrimidine (DAPY) nonnucleoside reverse transcriptase inhibitor (NNRTI) that is highly effective in treating wild-type and drug-resistant HIV-1 infections in clinical trials at relatively low doses (∼25–75 mg/day). We have determined the structure of wild-type HIV-1 RT complexed with TMC278 at 1.8 Å resolution, using an RT crystal form engineered by systematic RT mutagenesis. This high-resolution structure reveals that the cyanovinyl group of TMC278 is positioned in a hydrophobic tunnel connecting the NNRTI-binding pocket to the nucleic acid-binding cleft. The crystal structures of TMC278 in complexes with the double mutant K103N/Y181C (2.1 Å) and L100I/K103N HIV-1 RTs (2.9 Å) demonstrated that TMC278 adapts to bind mutant RTs. In the K103N/Y181C RT/TMC278 structure, loss of the aromatic ring interaction caused by the Y181C mutation is counterbalanced by interactions between the cyanovinyl group of TMC278 and the aromatic side chain of Y183, which is facilitated by an ∼1.5 Å shift of the conserved Y
183
MDD motif. In the L100I/K103N RT/TMC278 structure, the binding mode of TMC278 is significantly altered so that the drug conforms to changes in the binding pocket primarily caused by the L100I mutation. The flexible binding pocket acts as a molecular “shrink wrap” that makes a shape complementary to the optimized TMC278 in wild-type and drug-resistant forms of HIV-1 RT. The crystal structures provide a better understanding of how the flexibility of an inhibitor can compensate for drug-resistance mutations.
A direct link between carbohydrate utilization and virulence in the major human pathogen group A
Streptococcus
Authors: Shelburne Samuel A. , Keith David , Horstmann Nicola , Sumby Paul , Davenport Michael T. , Graviss Edward A. , Brennan Richard G. , Musser James M.
Published: January 2008

Although central to pathogenesis, the molecular mechanisms used by microbes to regulate virulence factor production in specific environments during host–pathogen interaction are poorly defined. Several recent
ex vivo
and
in vivo
studies have found that the level of group A
Streptococcus
(GAS) virulence factor gene transcripts is temporally related to altered expression of genes encoding carbohydrate utilization proteins. These findings stimulated us to analyze the role in pathogenesis of catabolite control protein A (CcpA), a GAS ortholog of a key global regulator of carbohydrate metabolism in
Bacillus subtilis
. Inasmuch as the genomewide effects of CcpA in a human pathogen are unknown, we analyzed the transcriptome of a Δ
ccpA
isogenic mutant strain grown in nutrient-rich medium. CcpA influences the transcript levels of many carbohydrate utilization genes and several well characterized GAS virulence factors, including the potent cytolysin streptolysin S. Compared with the wild-type parental strain, the Δ
ccpA
isogenic mutant strain was significantly less virulent in a mouse model of invasive infection. Moreover, the isogenic mutant strain was significantly impaired in ability to colonize the mouse oropharynx. When grown in human saliva, a nutrient-limited environment, CcpA influenced production of several key virulence factors not influenced during growth in nutrient-rich medium. Purified recombinant CcpA bound to the promoter region of the gene encoding streptolysin S. Our discovery that GAS virulence and complex carbohydrate utilization are directly linked through CcpA provides enhanced understanding of a mechanism used by a Gram-positive pathogen to modulate virulence factor production in specific environments.
Influence of affective valence on working memory processes
Authors: Gotoh Fumiko
Published: January 2008

Recent research has revealed widespread effects of emotion on cognitive function and memory. However, the influence of affective valence on working or short‐term memory remains largely unexplored. In two experiments, the present study examined the predictions that negative words would capture attention, that attention would be difficult to disengage from such negative words, and that the cost of attention switching would increase the time required to update information in working memory. Participants switched between two concurrent working memory tasks: word recognition and a working memory digit updating task. Experiment 1 showed substantial switching cost for negative words, relative to neutral words. Experiment 2 replicated the first experiment, using a self‐report measure of anxiety to examine if switching cost is a function of an anxiety‐related attention bias. Results did not support this hypothesis. In addition, Experiment 2 revealed switch costs for positive words without the effect of the attention bias from anxiety. The present study demonstrates the effect of affective valence on a specific component of working memory. Moreover, findings suggest why affective valence effects on working memory have not been found in previous research.
Long‐term immigrant adaptation: Eight‐year follow‐up study among immigrants from Russia and Estonia living in Finland
Authors: Jasinskaja‐Lahti Inga
Published: January 2008

This study was a longitudinal investigation of the three different dimensions of long‐term immigrant adaptation (i.e., psychological, sociocultural, and socioeconomic adaptation) and the relationships between them in an 8‐year follow‐up with panel data. The 282 respondents were immigrants in Finland, born between 1961 and 1976, coming from the former Soviet Union. The results suggest that the adaptation of these immigrants has developed favourably. In 8 years, the respondents had improved their Finnish language skills and their position in the labour market. No differences were observed in their levels of psychological well‐being between the two assessments. Of the three adaptation dimensions assessed, sociocultural adaptation, measured as proficiency in understanding, speaking, reading, and writing Finnish, turned out to be the most significant predictor of the two other long‐term outcomes of immigrant adaptation (i.e., socioeconomic and psychological). In particular, the better the initial command of the Finnish language, the better were their socioeconomic and psychological adaptation outcomes after 8 years of residence. These results demonstrate the importance of parallel and longitudinal assessments of the different outcomes of immigrant adaptation in order to address which particular dimensions of adaptation are most critical in the beginning of acculturation in terms of determining positive development and long‐term immigrant adaptation.
Identification and analysis of transport domains in the stochastic boundary of TEXTOR-DED for different mode spectra
Authors: Schmitz O. , Jakubowski M.W. , Frerichs H. , Harting D. , Lehnen M. , Unterberg B. , Abduallaev S.S. , Brezinsek S. , Classen I. , Evans T. , Feng Y. , Finken K.H. , Kantor M. , Reiter D. , Samm U. , Schweer B. , Sergienko G. , Spakman G.W. , Tokar M. , Uzgel E. , Wolf R.C.
Published: January 2008

At the TEXTOR tokamak an external resonant magnetic perturbation is applied with the dynamic ergodic divertor to control the edge transport properties. The approaches to analyse the impact of such a kind of edge stochastization on transport apply mostly a shell-like picture which includes a dependence of transport from magnetic field topology in the radial direction only. In this paper multiple experimental evidence is presented in contrast to these approaches the perturbation applied forms a poloidally heterogenous edge layer in which the transport characteristics are determined by the poloidally alternating field line behaviour. A thorough analysis of density and temperature profiles and their gradients for base mode spectra with poloidal/toroidal mode numbers ofm/n= 12/4 andm/n= 6/2 is worked out in comparison with the modelled magnetic field topology and results from three dimensional transport modelling with EMC3/EIRENE. Hereby two poloidally adjacent transport domains are identified for the first time in such detail. A domain representing a helical scrape off layer is formed by field lines with short connection and therefore prevailing parallel transport to the wall elements. Here, the field lines are clustered into extended flux tubes embedded into a long connection length ergodic domain with diffusive transport characteristics and enhanced radial transport.
Irreducible representations of finite spin groups
Authors: Lusztig G.
Published: January 2008

In this paper we present a computation (done by the author in 1983) which yields a multiplicity one statement for the irreducible representations of a finite spin group which, in turn, yields the classification of the irreducible representations of a finite spin group.
Integrating genetic and epidemiological data to determine transmission pathways of foot-and-mouth disease virus
Authors: Cottam Eleanor M , Thébaud Gaël , Wadsworth Jemma , Gloster John , Mansley Leonard , Paton David J , King Donald P , Haydon Daniel T
Published: January 2008

Estimating detailed transmission trees that reflect the relationships between infected individuals or populations during a disease outbreak often provides valuable insights into both the nature of disease transmission and the overall dynamics of the underlying epidemiological process. These trees may be based on epidemiological data that relate to the timing of infection and infectiousness, or genetic data that show the genetic relatedness of pathogens isolated from infected individuals. Genetic data are becoming increasingly important in the estimation of transmission trees of viral pathogens due to their inherently high mutation rate. Here, we propose a maximum-likelihood approach that allows epidemiological and genetic data to be combined within the same analysis to infer probable transmission trees. We apply this approach to data from 20 farms infected during the 2001 UK foot-and-mouth disease outbreak, using complete viral genome sequences from each infected farm and information on when farms were first estimated to have developed clinical disease and when livestock on these farms were culled. Incorporating known infection links due to animal movement prior to imposition of the national movement ban results in the reduction of the number of trees from 41 472 that are consistent with the genetic data to 1728, of which just 4 represent more than 95% of the total likelihood calculated using a model that accounts for the epidemiological data. These trees differ in several ways from those constructed prior to the availability of genetic data.
The systematic position of Lauroiinae Skrjabin and Schikhobalova, 1951 (Nemata: Heterakoidea: Aspidoderidae), as revealed by the analysis of traits used in its diagnosis
Authors: Jiménez‐Ruiz F. Agustín , Gardner Scott L. , Noronha Dely , Pinto Roberto Magalhães
Published: January 2008

During our work on biodiversity of parasites of mammals of the Neotropics we collected numerous nematodes assignable to species of the family Aspidoderidae (Nemata: Heterakoidea). These nematodes occur as parasites of the cecum and large intestine of marsupials, rodents and xenarthrans (armadillos) only in the New World. As aspidoderid nematodes have been little studied beyond their alpha taxonomy, it is the purpose of the present paper to apply phylogenetic systematic methods to more completely understand the evolutionary relationships of the included species. Members of the aspidoderid subfamily Lauroiinae have had very little work applied to their systematic relationships and no systematic revisions exist that include all recognized species. Diagnostic characters that define species in this subfamily include plate‐like cuticular structures on the anterior end. Herein we define a suite of 52 characters derived from studies of specimens using both light and electron microscopy. Our phylogenetic systematic analysis included the eight known species in the Lauroiinae, seven of the Aspidoderinae and four outgroup taxa. The results indicate that the Lauroiinae is paraphyletic, that the cephalic plates on the anterior end are not synapomorphies for the Lauroiinae, and that structures forming the cordon are present in all species of the family. We propose elimination of the subfamily designations in the family Aspidoderidae and we show the utility of using additional characters in the diagnosis of the family and the genera within this family. The resulting hypothesis should serve as the foundation to understand the historical associations of the nematodes with the mammals they infect.

© The Willi Hennig Society 2008.
Multivariate analysis of CPMAS 13C‐NMR spectra of soils and humic matter as a tool to evaluate organic carbon quality in natural systems
Authors: ŠMejkalová D. , Spaccini R. , Piccolo A.
Published: January 2008

A series of humic and fulvic acids isolated from different sources, size‐fractions separated from a humic acid, and three soils of different origin were subjected to CPMAS 13C‐NMR spectroscopy to obtain the distribution of their carbon contents. The relative areas of chemical shift regions in NMR spectra were used to apply a principal component analysis (PCA) to the three sets of samples. The multivariate analysis was successful in efficiently differentiating samples on the basis of the quality of their organic carbon content. The PC biplots based on two principal components distinguished objectively among samples as accurately as it was possible to do by subjective qualitative evaluation of the original spectra. In the case of the soils, a discriminant analysis (DA) was applied to build a classification model that allowed the validation of the three soils according to their origin. Percentage of validation in the classification model is expected to increase when a large number of NMR spectra are accumulated and/or the concentration of organic carbon in samples is enhanced. The multivariate analyses described are likely to become a useful tool to increase the importance of CPMAS 13C‐NMR spectra in the appraisal of natural organic matter variations in heterogeneous natural systems.
Microsatellite analysis of relatedness structure in young of the year of the endangered Zingel asper (Percidae) and implications for conservation
Authors: DANANCHER DELPHINE , IZQUIERDO JORGE I. , GARCIA‐VAZQUEZ EVA
Published: January 2008

1. Zingel asper is one of the most endangered freshwater fish of Western Europe. Because of critical habitat loss and fragmentation, stocking or reintroduction protocols are sometimes considered even though few data are available about the behaviour and biology of the species.

2. The present study is the first attempt to explore the population genetic structure of juveniles (young of the year, YOY) of this endangered species using genetic markers (microsatellite loci). In the Beaume River (ardeche, France), Z. asper exhibits very low densities (10–80 fish per hectare), and it was expected that annual recruitment would comprise only few clutches (full‐ or half‐sibs groups).

3. However, sibship reconstruction in one YOY cohort showed that more than 60% of the adult population reproduced. Dispersal rate in early YOY was high: relatedness estimates showed that only few months after hatching, YOY sibs were mixed among study sites. A large number of breeders together with high dispersal rates explain the high genetic variability observed in small populations of Z. asper.

4. Conservation strategies for the species are discussed based on these results, emphasizing the importance of conserving population genetic variability and preserving habitat connectivity for juveniles.
Testing species–stone area and species–bryophyte cover relationships in riverine macroinvertebrates at small scales
Authors: HEINO JANI , KORSU KAI
Published: January 2008

1. The species–area relationship is considered amongst the few genuine laws in ecology. Although positive species richness–stone area relationships have been found previously in stream systems, very few studies have simultaneously examined species–individuals, individuals–area, species–bryophyte biomass and individuals–bryophyte biomass relationships. We examined these relationships based on temporally replicated assessments of macroinvertebrates on stones at two river sites.

2. We found only one significant species–area relationship out of six relationship tested, and two significant individuals–area relationships. Even these significant relationships were weak, however. By contrast, we detected significant and rather strong relationships between species richness and the number of individuals at both river sites on all three sampling dates. We also found significant relationships of both species richness and the number of individuals with bryophyte biomass at both river sites on all sampling occasions. One of the river sites was disturbed by a bulldozer, and the species–bryophyte biomass relationships were somewhat stronger after the disturbance event.

3. Our findings are quite surprising, given that there were very weak species–area relationships on stream stones. By contrast, our results suggest a pivotal role for bryophyte biomass in determining the species richness and the number of individuals of stream macroinvertebrates at this small scale. The most probably origin of these relationships begins with bryophyte cover, which determines the number of individuals, and subsequently passively affects species richness. Thus, there is not necessarily a direct mechanism that determines the variability of species richness on stream stones.

4. Experimental studies are needed to disentangle the various mechanisms (e.g. passive sampling, provision of more food, more niche space, flood disturbance refugia) by which bryophyte biomass affects stream macroinvertebrates.
Predicting the locations of naturally fishless lakes
Authors: SCHILLING EMILY GAENZLE , LOFTIN CYNTHIA S. , DEGOOSH KATIE E. , HURYN ALEXANDER D. , WEBSTER KATHERINE E.
Published: January 2008

1. Fish have been introduced into many previously fishless lakes throughout North America over the past 100+ years. It is difficult to determine the historical distribution of fishless lakes, however, because these introductions have not always been well‐documented.

2. Due to its glacial history and low human population density, the state of Maine (U.S.A.) may host the greatest number of naturally fishless lakes in the northeastern United States. However, less than one‐quarter of Maine’s 6000+ lakes have been surveyed for fish presence, and no accurate assessments of either the historical or current abundance and distribution of fishless lakes exist.

3. We developed methods to assess the abundance and distribution of Maine’s naturally fishless lakes (0.6–10.1 ha). We hypothesized that the historical distribution of fishless lakes across a landscape is controlled by geomorphic and geographic conditions.

4. We used ArcGIS to identify landscape‐scale geomorphic and geographic factors (e.g. connectivity, surrounding slope) correlated with fish absence in two geomorphic regions of Maine – the western and interior mountains and the eastern lowlands and foothills. By using readily available geographic information systems data our method was not limited to field‐visited sites. We estimated the likelihood that a particular lake is fishless with a stepwise logistic regression model developed for each region.

5. The absence of fish from western lakes is related to altitude (+), minimum percent slope in the 500 m buffer (+), maximum percent slope in the 500 m buffer (+) and percent cover of herbaceous‐emergent wetland in 1000 m buffer (−). The absence of fish from eastern lakes is related to the lack of a stream within 50 m of the lake.

6. The models predict that a total of 4% (131) of study lakes in the two regions were historically fishless, with the eastern region hosting a greater proportion than the western region.

7. We verified the model predictions with two complementary approaches. First we visited 21 lakes predicted to be fishless and assessed current fish presence with gillnetting. Second, we used paleolimnological techniques based on the abundance of Chaoborus americanus mandibles in the bottom segments of sediment cores. Fifteen of the 21 lakes predicted to be fishless currently contain fish. Paleolimnological evidence, however, suggests that nine of the 15 lakes were historically fishless and thus were subject to undocumented fish introductions.

8. Our approach efficiently predicts the distribution Maine’s naturally fishless lakes, and our results indicate that these habitats have declined due to fish introductions. Our method could be applied to other regions with similar geographic and geomorphic constraints on fish distributions as a tool to enhance conservation of a limited resource that provides habitat for unique biological communities.
Rsp5 is required for the nuclear export of mRNA of HSF1 and MSN2/4 under stress conditions in Saccharomyces cerevisiae
Authors: Haitani Yutaka , Takagi Hiroshi
Published: January 2008

Rsp5 is an essential and multi‐functional E3 ubiquitin ligase in Saccharomyces cerevisiae. We previously isolated the Ala401Glu rsp5 mutant that is hypersensitive to various stresses. In rsp5A401E cells, the transcription of the stress protein genes was defective. To understand the mechanism by which Rsp5 regulates the expression of stress proteins, we analyzed the expression and localization of two major transcription factors, Hsf1 and Msn2/4, required for stress protein gene expression in S. cerevisiae. The mRNA levels of HSF1 and MSN2/4 in rsp5A401E cells were slightly lower than those of wild‐type cells. An interesting finding is that the protein levels of HSF1 and Msn2/4 were remarkably defective in rsp5A401E cells after exposure to temperature up‐shift and ethanol, although these proteins are mainly localized in the nucleus under these stress conditions. We also showed that the mRNAs of HSF1 and MSN2/4 were accumulated in the nucleus of rsp5A401E cells after exposure to temperature up‐shift and ethanol, and even under non‐stress conditions, suggesting that Rsp5 is required for the nuclear export of these mRNAs. These results indicate that, in response to environmental stresses, Rsp5 primarily regulates the expression of Hsf1 and Msn2/4 at the post‐transcriptional level and is involved in the repair system of stress‐induced abnormal proteins.
Transcription factor NF‐Y is involved in regulation of the JNK pathway during Drosophila thorax development
Authors: Yoshioka Yasuhide , Suyari Osamu , Yamaguchi Masamitsu
Published: January 2008

The CCAAT motif‐binding factor, nuclear factor Y (NF‐Y) consists of three different subunits, NF‐YA, NF‐YB and NF‐YC. Knockdown of Drosophila NF‐YA (dNF‐YA) in the notum compartment of wing discs by a pannir‐GAL4 and UAS‐dNF‐YAIR mainly resulted in a thorax disclosed phenotype. Reduction of the Drosophila c‐Jun N‐terminal kinase (JNK) basket (bsk) gene dose enhanced the knockdown of dNF‐YA‐induced phenotype. Monitoring of JNK activity in the wing disc by LacZ expression in a puckered (puc)‐LacZ enhancer trap line revealed reduction in the level of the JNK reporter, puc‐LacZ signals, in dNF‐YA RNAi clones. In addition, expression of wild‐type Bsk effectively suppressed the phenotype induced by knockdown of dNF‐YA. The bsk gene promoter contains a CCAAT motif and this motif plays a positive role in the promoter activity. We performed chromatin immunoprecipitation (ChIP) assays in S2 cells with anti‐dNF‐YA IgG and quantitative real‐time PCR. The bsk gene promoter region containing the CCAAT boxes was effectively amplified in the immunoprecipitates by PCR. However, this region was not amplified in the immunoprecipitates from dNF‐YA knockdown cells. Furthermore, the level of endogenous bsk mRNA is reduced in the dNF‐YA knockdown larvae. These results suggest that dNF‐Y is necessary for proper bsk expression and activity of JNK pathway during thorax development.
Reduced BMP4 abundance in Gata2 hypomorphic mutant mice result in uropathies resembling human CAKUT
Authors: Hoshino Tomofumi , Shimizu Ritsuko , Ohmori Shinya , Nagano Masumi , Pan Xiaoqing , Ohneda Osamu , Khandekar Melin , Yamamoto Masayuki , Lim Kim‐Chew , Engel James Douglas
Published: January 2008

Constitutive loss of transcription factor GATA‐2 leads to embryonic lethality from primitive erythropoietic failure. We serendipitously discovered an essential contribution of GATA‐2 to urogenital development when the hematopoietic deficiency of Gata2 null mutant animals was complemented by a Gata2 yeast artificial chromosome (YAC) transgene; these mice died from a perinatal lethal urogenital abnormality. Here, we report the generation and analysis of Gata2 hypomorphic mutant (Gata2fGN/fGN) mice, which suffered from hydronephrosis and megaureter, as do the YAC‐rescued Gata2 null mutants. Gata2fGN/fGN mutants exhibit anteriorly displaced ureteric budding from the Wolffian duct as well as reduced BMP4 expression in the intermediate mesoderm derivatives in a manner that is temporally coincident with ureteric bud emergence. In Bmp4 mutant heterozygotes, rostral displacement of the initial bud site on the Wolffian duct results in abnormal urogenital development. We show here that Bmp4 mRNA is reduced approximately twofold in Gata2fGN/fGN mice (as in Bmp4 null heterozygotes), and that GATA‐2 trans‐activates a Bmp4 first intron element‐directed reporter plasmid in co‐transfection assays. These experiments taken together implicate GATA‐2 as a direct regulator of Bmp4 transcription. The pathophysiology described in Gata2 hypomorphic mutant animals resembles human congenital anomalies of the kidney and urinary tract.
C‐terminal truncation of the peroxiredoxin Tpx1 decreases its sensitivity for hydrogen peroxide without compromising its role in signal transduction
Authors: Jara Mónica , Vivancos Ana P. , Hidalgo Elena
Published: January 2008

Peroxiredoxins (Prxs) participate in hydrogen peroxide (H2O2) scavenging. Eukaryotic Prxs suffer H2O2‐dependent inactivation, due to the oxidation of its catalytic cysteine to sulfinic acid, a modification which can be enzymatically reversed. This substrate‐mediated reversible inactivation has been suggested to allow eukaryotic Prxs to act as floodgates, permitting high levels of H2O2 to trigger signal transduction. To test this hypothesis, we used the fission yeast Prx Tpx1, which acts as a H2O2 scavenger during aerobic metabolism and also participates in peroxide‐induced signal transduction pathways. High concentrations of peroxide reversibly inactivate Tpx1.Here, we describe the characterization of a Tpx1 derivative, which lacks a carboxy‐terminal extension present only in eukaryotic Prxs. This mutant protein is not inactivated by high doses of H2O2. Exclusive expression of this truncated version of Tpx1 is deleterious for aerobic growth, but H2O2‐dependent signal transduction is not impaired in this strain. Instead, the ability of Tpx1.ΔCTD to detect and detoxify peroxides is impaired. Our results indicate that inactivation of Tpx1 by excess peroxides is not required for H2O2 signaling towards the Sty1 pathway, as expected from the floodgate model, and that the carboxy‐terminal extension of Tpx1 concomitantly improves H2O2 scavenging and increases susceptibility to inactivation.
Climatic change and fire potential in South‐Central British Columbia, Canada
Authors: NITSCHKE CRAIG R. , INNES JOHN L.
Published: January 2008

The incidence and severity of forest fires are linked to the interaction between climate, fuel and topography. Increased warming and drying in the future is expected to have a significant impact on the risk of forest fire occurrence. An increase in fire risk is linked to the synchronous relationship between climate and fuel moisture conditions. A warmer, drier climate will lead to drier forest fuels that will in turn increase the chance of successful fire ignition and propagation. This interaction will increase the severity of fire weather, which, in turn, will increase the risk of extreme fire behaviour. A warmer climate will also extend fire season length, which will increase the likelihood of fires occurring over a greater proportion of the year. In this study of the North Okanagan area of British Columbia, Canada, the impacts of climate change of fire potential were evaluated using the Canadian Forest Fire Danger Rating System and multiple climate scenario analysis. Utilizing this approach, a 30% increase in fire season length was modelled to occur by 2070. In addition, statistically significant increases in fire severity and fire behaviour were also modelled. Fire weather severity was predicted to increase by 95% during the summer months by 2070 while fire behaviour was predicted to shift from surface fire‐intermittent crown fire regimes to a predominantly intermittent‐full crown fire regime by 2070 onwards. An increase in fire season length, fire weather severity and fire behaviour will increase the costs of fire suppression and the risk of property and resource loss while limiting human‐use within vulnerable forest landscapes. An increase in fire weather severity and fire behaviour over a greater proportion of the season will increase the risks faced by ecosystems and biodiversity to climatic change and increase the costs and difficulty of achieving sustainable forest management.
European principles of haemophilia care
Authors: COLVIN B. T. , ASTERMARK J. , FISCHER K. , GRINGERI A. , LASSILA R. , SCHRAMM W. , THOMAS A. , INGERSLEV J. ,   FOR THE INTER DISCIPLINARY WORKING GROUP
Published: January 2008

Summary.  As the management of haemophilia is complex, it is essential that those with the disorder should have ready access to a range of services provided by a multidisciplinary team of specialists. This document sets out the principles of comprehensive haemophilia care in Europe. Within each country there should be a national organization which oversees the provision of specialist Comprehensive Care Centres that provide the entire spectrum of clinical and laboratory services. Depending upon the size and geographical distribution of the population, a network of smaller haemophilia centres may also be necessary. There should be arrangements for the supply of safe clotting factor concentrates which can also be used in home treatment and prophylaxis programmes. A national register of patients is recommended along with collection of treatment statistics. As comprehensive haemophilia care is multidisciplinary by nature, the need for education and research programmes for all staff members is emphasized: Members of the Interdisciplinary Working Group not represented in the list of authors are mentioned in Section 4 of this document.
Subsequent publication of abstracts presented at the International Association of Paediatric Dentistry meetings
Authors: DAHLLÖF GÖRAN , WONDIMU BINIYAM , MANIERE MARIE‐CÉCILE
Published: January 2008

Background.  Presentation of scientific information at international meetings is important for the dissemination of new scientific research. It is often assumed that the information contained in an abstract will subsequently be published in a scientific journal in full‐length form.

Objective.  The aim of this investigation was to study the publication rate of abstracts presented to the International Association of Paediatric Dentistry (IAPD) congresses in London 1999 and Paris 2001, and factors that predict subsequent publication were also investigated.

Materials and methods.  Abstracts presented at the IAPD congresses were reviewed. A Medline/PubMed search, encompassing 1999–2006, was performed.

Results.  At the two IAPD congresses, a total of 771 abstracts were presented, 231 (30%) as oral presentations, 327 (42%) as poster discussion presentations, and 212 (28%) as poster presentations. During the period studied, 204 (27%) of the 771 abstracts were expanded into articles published in Medline/PubMed indexed journals. The publication ratio for orally presented abstracts was 40%, poster discussion presentation 21%, and for poster presentations 19% (P < 0.0001). The mean time from the congress to publication was 20 months.

Conclusion.  The results of this study show that 40% of orally presented abstracts at IAPD congresses were followed by a subsequent scientific publication in a peer‐reviewed journal.
Phase‐locked mutants of Mycoplasma agalactiae: defining the molecular switch of high‐frequency Vpma antigenic variation
Authors: Chopra‐Dewasthaly Rohini , Citti Christine , Glew Michelle D. , Zimmermann Martina , Rosengarten Renate , Jechlinger Wolfgang
Published: January 2008

Mycoplasma agalactiae, an important pathogen of small ruminants, exhibits antigenic diversity by switching the expression of multiple surface lipoproteins called Vpmas (Variable proteins of M. agalactiae). Although phase variation has been shown to play important roles in many host–pathogen interactions, the biological significance and the mechanism of Vpma oscillations remain largely unclear. Here, we demonstrate that all six Vpma proteins are expressed in the type strain PG2 and all undergo phase variation at an unusually high frequency. Furthermore, targeted gene disruption of the xer1 gene encoding a putative site‐specific recombinase adjacent to the vpma locus was accomplished via homologous recombination using a replicon‐based vector. Inactivation of xer1 abolished further Vpma switching and the ‘phase‐locked’ mutants (PLMs) continued to steadily express only a single Vpma product. Complementation of the wild‐type xer1 gene in PLMs restored Vpma phase variation thereby proving that Xer1 is essential for vpma inversions. The study is not only instrumental in enhancing our ability to understand the role of Vpmas in M. agalactiae infections but also provides useful molecular approaches to study potential disease factors in other ‘difficult‐to‐manipulate’ mycoplasmas.
A decrease of plasma macrophage migration inhibitory factor concentration is associated with lower numbers of circulating lymphocytes in experimental Plasmodium falciparum malaria
Authors: DE MAST Q. , SWEEP F. C. G. J. , McCALL M. , GEURTS‐MOESPOT A. , HERMSEN C. , CALANDRA T. , NETEA M. G. , SAUERWEIN R. W. , VAN DER VEN A. J. M.
Published: January 2008

Macrophage migration inhibitory factor (MIF) has recently been implicated in the pathogenesis of malarial anaemia. However, field studies have reported contradictory results on circulating MIF concentrations in patients with clinically overt Plasmodium falciparum malaria. We determined plasma MIF levels over time in 10 healthy volunteers during experimental P. falciparum infection. Under fully controlled conditions, MIF levels decreased significantly during early blood‐stage infection and reached a nadir at day 8 post‐infection. A decrease in the number of circulating lymphocytes, which are an important source of MIF production, paralleled the decrease in MIF levels. Monocyte/macrophage counts remained unchanged. At MIF nadir, the anti‐inflammatory cytokine interleukin (IL)‐10, which is an inhibitor of T‐cell MIF production, was detectable in only 2 of 10 volunteers. Plasma concentrations of the pro‐inflammatory cytokines IL‐8 and IL‐1β were only marginally elevated. We conclude that circulating MIF levels decrease early in blood‐stage malaria as a result of the decline in circulating lymphocytes.
Mechanisms of leucocyte recruitment to the inflamed large intestine: redundancy in integrin and addressin usage
Authors: BELL L. V. , ELSE K. J.
Published: January 2008

The caecal‐dwelling nematode Trichuris muris provides a natural model of human whipworm infection. Resistance to T. muris is dependent on a host Th2 response, and CD4+Th2 cells migrate to the gut‐associated lymphoid tissue (GALT) to elicit parasite expulsion. Thus, CD4+T cells infiltrate the caecal lamina propria during infection, along with other leucocyte subsets that are not critical for parasite expulsion, such as eosinophils. Trafficking of leucocytes to the GALT has been shown to be dependent on the α4β7/MAdCAM‐1 integrin–addressin interaction. However, where inflammation is present, such as during T. muris infection, redundant mechanisms of leucocyte recruitment may also occur in addition to traditional gut‐homing interactions. We utilized an anti‐integrin/addressin antibody treatment regime to investigate this redundancy in resistant, T. muris‐infected C57BL/6 mice. Where only the α4β7/MAdCAM‐1 interaction was blocked, mice remained resistant to T. muris infection, making a Th2 response and both CD4+T cells and eosinophils infiltrated the site of infection. However, in the absence of available α4β7 and α4β1, mice became chronically infected with T. muris and mounted a more Th1‐biased immune response. Interestingly, CD4+T cells, but not eosinophils, were able to infiltrate the caecum, showing different levels of redundancy between leucocyte subsets during infection.
ARL2, ARG1 and PIN3 define a gravity signal transduction pathway in root statocytes
Authors: Harrison Benjamin R. , Masson Patrick H.
Published: January 2008

ALTERED RESPONSE TO GRAVITY1 (ARG1) and its paralog ARG1‐LIKE2 (ARL2) are J‐domain proteins that are required for normal root and hypocotyl gravitropism. In this paper, we show that both ARL2 and ARG1 function in a gravity signal transduction pathway with PIN3, an auxin efflux facilitator that is expressed in the statocytes. In gravi‐stimulated roots, PIN3 relocalizes to the lower side of statocytes, a process that is thought to, in part, drive the asymmetrical redistribution of auxin toward the lower flank of the root. We show that ARL2 and ARG1 are required for PIN3 relocalization and asymmetrical distribution of auxin upon gravi‐stimulation. ARL2 is expressed specifically in the root statocytes, where it localizes to the plasma membrane. Upon ectopic expression, ARL2 is also found at the cell plate of dividing cells during cytokinesis, an area of intense membrane dynamics. Mutations in ARL2 and ARG1 also result in auxin‐related expansion of the root cap columella, consistent with a role for ARL2 and ARG1 in regulating auxin flux through the root tip. Together these data suggest that ARL2 and ARG1 functionally link gravity sensation in the statocytes to auxin redistribution through the root cap.
Sponge and coral zooxanthellae in heat and light: preliminary results of photochemical efficiency monitored with pulse amplitude modulated fluorometry
Authors: Schönberg Christine H. L. , Suwa Ryota , Hidaka Michio , Loh William Kok Weng
Published: January 2008

Photochemical efficiency (Fv/Fm) was compared between a common symbiotic bioeroding sponge, Cliona cf. orientalis, and a common reef‐builder, Acropora palifera using pulse amplitude modulated fluorescence (PAM). The study was conducted on Sesoko Island, Okinawa, where reefs were severely damaged during previous bleaching episodes. Sponge and coral dinoflagellate symbionts were treated with heat and light in a tank experiment, both in hospite (=still within their host) and isolated from their hosts. We found significant differences for photochemical efficiency of holobionts (=host and symbiont together) compared to the isolate symbionts and over time. All symbionts suffered in isolation and displayed stronger reactions to the treatments, and there was evidence for increasing damage despite returning to control conditions. However, because of large variability of the bi‐symbiont coral samples and restrictions of the experimental design, our main results remained inconclusive, with no significant differences between sponge and coral samples and between the different stress treatments. Judging the results based on the uniform trends in the subsets of data, the G‐clade sponge symbionts appeared to be more stress tolerant than the C‐ and D‐clade coral symbionts, with no treatment effects in hospite and less damage in isolation compared to the coral symbionts, but this is an unconfirmed assumption. Isolated sponge symbionts were very resistant against heat stress, but may have suffered from light stress. In hospite, the latter risk can be countered by the sponge’s 3‐dimensional morphology, the endolithic life style that affords shading, and by behavioural adaptation, i.e. the ability to move symbionts away from the source of stress. Overall, C. cf. orientalis symbionts displayed a more stable photochemical efficiency during and after stress than those of A. palifera. Results of this study suggest that with climate change C. cf. orientalis might have a better survival potential than A. palifera, but further investigations are necessary.