bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and theoretical studies of surface phonon polariton of AlN thin film
Authors: Ng S. S. , Hassan Z. , Abu Hassan H.
Published: February 2007

The surface phonon polariton (SPP) mode of aluminum nitride (AlN) thin film grown on sapphire substrate is investigated experimentally and theoretically. For the experimental study, p-polarized infrared attenuated total reflection measurements are performed. A strong absorption dip which corresponds to the SPP mode of AlN thin film is clearly observed at 839.0cm−1. For the theoretical study, the surface-polariton dispersion curve of the AlN thin film has been simulated. Finally, the experimental and theoretical values of the SPP mode are compared. The results revealed that the uncertainty between the theoretical and experimental SPP values is less than 2%.
Fabrication of epitaxial and transparent Pb(Zr0.52Ti0.48)O3 ferroelectric capacitors with La0.07Sr0.93SnO3 electrodes
Authors: Chen Feng , Wang H. F. , Liu Q. Z. , Wu Wenbin , Li X.-G.
Published: February 2007

Conductive and transparent La0.07Sr0.93SnO3 (LSSO) films were employed as electrodes for the fabrication of epitaxial Pb(Zr0.52Ti0.48)O3 (PZT) ferroelectric capacitors. Due to a negligible lattice mismatch between LSSO and PZT, the LSSO/PZT/LSSO heterostructures grown on SrTiO3(001) substrates show excellent single-crystalline quality as revealed by high-resolution x-ray diffraction and are transparent with transmittance comparable to that of pure SrTiO3(001) substrates at the wavelength of 400–2500nm. These capacitors show square polarization–electric field hysteresis loops but smaller polarization, larger coercive field, and especially poor fatigue resistance, in sharp contrast with those observed for the conventional epitaxial all-oxide PZT capacitors.
Effect of high temperatures on seed germination and seedling survival in three pine species (Pinus pinaster, P. sylvestris and P. nigra)
Authors: Alvarez R. , Valbuena L. , Calvo L.
Published: February 2007

In the present study, we analyse the germination and seedling growth of three Pinus species (P. pinaster, P. sylvestris and P. nigra) under laboratory conditions after thermal shocks simulating the temperature effects of fire. Temperatures up to 150°C and 5 min exposure show negative effects on the percentage germination of P. pinaster seeds. P. sylvestris and P. nigra cannot stand temperatures greater than 110°C and 5 min exposure. In all three species, thermal shocks delay the start of germination. In addition, seeds from P. pinaster germinate over a longer time range. Seedling aerial growth after germination is influenced by high temperatures in P. sylvestris and P. nigra, but not in P. pinaster. Finally, thermal shocks produce a reduction in root growth in comparison with aerial growth in P. sylvestris.
Continuous-index hidden Markov modelling of array CGH copy number data
Authors: Stjernqvist Susann , Rydén Tobias , Sköld Martin , Staaf Johan
Published: February 2007

Motivation: In recent years, a range of techniques for analysis and segmentation of array comparative genomic hybridization (aCGH) data have been proposed. For array designs in which clones are of unequal lengths, are unevenly spaced or overlap, the discrete-index view typically adopted by such methods may be questionable or improved.

Results: We describe a continuous-index hidden Markov model for aCGH data as well as a Monte Carlo EM algorithm to estimate its parameters. It is shown that for a dataset from the BT-474 cell line analysed on 32K BAC tiling microarrays, this model yields considerably better model fit in terms of lag-1 residual autocorrelations compared to a discrete-index HMM, and it is also shown how to use the model for e.g. estimation of change points on the base-pair scale and for estimation of conditional state probabilities across the genome. In addition, the model is applied to the Glioblastoma Multiforme data used in the comparative study by Lai et al. (Lai,W.R. et al. (2005) Comparative analysis of algorithms for identifying amplifications and deletions in array CGH data. Bioinformatics, 21, 3763–3370.) giving result similar to theirs but with certain features highlighted in the continuous-index setting.

Contact:  susann.stjernqvist@matstat.lu.se

Supplementary information: Supplementary data are available at Bioinformatics online.
A possible evolutionary lag in the relationship between freshwater mussels and European bitterling
Authors: Reichard M. , Przybylski M. , Kaniewska P. , Liu H. , Smith C.
Published: February 2007

The coevolutionary dynamics between European bitterlingRhodeus amarusand freshwater unionid mussels, which the former parasitize by laying eggs on their gills, were tested. In a series of experiments fish preferences and mussel responses were compared in parasites and hosts of recent (Europe) and ancient (Asia) sympatry.Rhodeus amarusreadily oviposited on the gills of all mussel species tested. Fish that laid their eggs on the gills of AsianAnodonta woodiana,however, suffered a dramatic reduction in reproductive success compared to fish that oviposited on the gills of European mussels:Unio pictorum,Unio tumidus,Anodonta anatinaandAnodonta cygnea. This difference was the result of egg ejection behaviour by mussels rather than the unsuitability of the internal gill environment for European bitterling embryo development. The ejection response of mussels with a long sympatry with European bitterling was considerably more pronounced than that of mussels with a substantially shorter sympatry. The data support a coevolutionary arms race between bitterling and mussels and point to an evolutionary lag in the relationship betweenR. amarusand its European mussel hosts.
Lipid and fatty acid composition during embryo and larval development of puye Galaxias maculatus Jenyns, 1842, obtained from estuarine, freshwater and cultured populations
Authors: Dantagnan H. , Bórquez A. S. , Valdebenito I. N. , Salgado I. A. , Serrano E. A. , Izquierdo M. S.
Published: February 2007

Galaxias maculatus eggs and larvae obtained from broodfish captured either in an estuarine or a freshwater environment, as well as from cultured broodstock were analysed to compare their lipid and fatty acid profiles. Results showed a lower lipid content in embryos and larvae from estuarine populations than those from fresh water, denoting the influence of environmental conditions. The n‐3:n‐6 ratio was higher in eggs from estuarine and cultured populations, being in the range of marine fishes, whereas for eggs from freshwater fish was lower and typical of freshwater fishes. The polyunsaturated fatty acids (PUFA), particularly docosahexaenoic acid (22:6n‐3) and eicosapentaenoic acid (20:5n‐3), were higher in eggs and larvae of broodstock coming from culture or estuarine environments than in those from fresh water. Moreover, these fatty acids markedly increased after hatching in larvae coming from estuarine populations, suggesting the effect of the environment on fatty acid profiles to physiologically prepare the larvae to adapt to higher salinity conditions. Linoleic acid (18:2n‐6) content was higher in fresh water fish and its reduction during embryo and larval development was accompanied by a significant increase of arachidonic acid (20:4n‐6), which was not observed in embryos or larvae from broodstock fish from estuary or aquaculture origin. Both environment and diet of broodstock fish affected lipid and fatty acid composition of G. maculatus embryo and larvae as well as their changes during development.
Changes in the life history of Abbottina rivularis in Lake Fuxian
Authors: Yan Y. Z. , Chen Y. F.
Published: February 2007

After invading Lake Fuxian, China, Abbottina rivularis showed marked changes in its life history traits, including alterations in annuli formation, extension to the length of the breeding season, and an increase in fecundity and growth rate. The results are explained in the context of the enemy release hypothesis.
Temperature and prey quality effects on growth of juvenile walleye pollock Theragra chalcogramma (Pallas): a spatially explicit bioenergetics approach
Authors: Mazur M. M. , Wilson M. T. , Dougherty A. B. , Buchheister A. , Beauchamp D. A.
Published: February 2007

A bioenergetics model for juvenile age‐0 year walleye pollock Theragra chalcogramma was applied to a spatially distinct grid of samples in the western Gulf of Alaska to investigate the influence of temperature and prey quality on size‐specific growth. Daily growth estimates for 50, 70 and 90 mm standard length (LS) walleye pollock during September 2000 were generated using the bioenergetics model with a fixed ration size. Similarities in independent estimates of prey consumption generated from the bioenergetics model and a gastric evacuation model corroborated the performance of the bioenergetics model, concordance correlation (rc) = 0·945, lower 95% CL (transformed) (L1) = 0·834, upper 95% CL (transformed) (L2) = 0·982, P < 0·001. A mean squared error analysis (MSE) was also used to partition the sources of error between both model estimates of consumption into a mean component (MC), slope component (SC), and random component (RC). Differences between estimates of daily consumption were largely due to differences in the means of estimates (MC= 0·45) and random sources (RC= 0·49) of error, and not differences in slopes (SC= 0·06). Similarly, daily growth estimates of 0·031–0·167 g day−1 generated from the bioenergetics model was within the range of growth estimates of 0·026–0·190 g day−1 obtained from otolith analysis of juvenile walleye pollock. Temperature and prey quality alone accounted for 66% of the observed variation between bioenergetics and otolith growth estimates across all sizes of juvenile walleye pollock. These results suggest that the bioenergetics model for juvenile walleye pollock is a useful tool for evaluating the influence of spatially variable habitat conditions on the growth potential of juvenile walleye pollock.
Starving early juvenile sprat Sprattus sprattus (L.) in western Baltic coastal waters: evidence from combined field and laboratory observations in August and September 2003
Authors: Baumann H. , Peck M. A. , Götze H.‐E. , Temming A.
Published: February 2007

Growth patterns inferred from otolith microstructure analysis were compared between sprat Sprattus sprattus early juveniles (26–42 mm total length, LT) collected in August 2003 in shallow coastal waters of the Kiel Fjord, and sprat recruits (60–95 mm LT) sampled in October during a pelagic trawl survey of the western Baltic Sea. At the end of August, a sudden and very rapid decline in otolith growth was observed in early juveniles but not in sprat recruits. Laboratory results indicated that the early juvenile fish were starving prior to capture. Specifically, when transferred to the laboratory, otolith growth rates immediately increased in fish provided ad libitum food rations, while otolith growth of starved fish continued to decline in the same manner observed prior to field collection. In addition, the vast majority of juvenile sprat had empty stomachs on the sampling day. Given that juveniles and recruits probably experienced similar temperature conditions, the rapid decline in juvenile growth rates presumably resulted from very poor feeding conditions in nearshore waters. Starvation during the early juvenile period has not been documented before, but may, at least in the case of Baltic sprat, comprise a density‐dependent mechanism operating in coastal nursery areas in some years.
Techniques for live capture of deepwater fishes with special emphasis on the design and application of a low‐cost hyperbaric chamber
Authors: Smiley J. E. , Drawbridge M. A.
Published: February 2007

A cost effective, simple, portable hyperbaric chamber was constructed from polyvinyl chloride to aid in the collection of adult rockfishes Sebastes sp. to hold as broodstock. This system was designed to recompress fishes quickly once brought to the surface on hook and line, and to allow for decompression over a period of days. The hyperbaric chamber is capable of continuous stable operation at <1 033 515 N m−2 and can accommodate fishes up to 91·4 cm in length and 26·8 cm in diameter. Pressure in the chamber is maintained by a Goulds Booster pump that delivers continuous pressure and supplies sea water at a rate of 3·8 to 7·6 l min−1 to as many as four chambers. The hyperbaric chamber operated very effectively and allowed successful decompression of 12 cowcod Sebastes levis captured at depths of 90·2 to 146·3 m.
The influence of turbidity on three‐spined stickleback foraging
Authors: Quesenberry N. J. , Allen P. J. , Cech J. J.
Published: February 2007

Three‐spined sticklebacksGasterosteus aculeatuswere used as a model to test for the effects of turbidity on visual‐predator foraging. While the number of feeding lunges and number of prey consumed did not change with increasing turbidity, reactive distance to prey decreased.
Blood cells of Murray cod Maccullochella peelii peelii (Mitchell)
Authors: Shigdar S. , Cook D. , Jones P. , Harford A. , Ward A. C.
Published: February 2007

Analysis of the peripheral blood cells of Murray cod Maccullochella peelii peelii identified seven distinct subpopulations including a novel basophilic cell. Haematological reference ranges were established to facilitate future diagnostic blood sampling of this fish.
Diet and feeding habits of predatory fishes upstream and downstream of a low‐level weir
Authors: Baumgartner L. J.
Published: February 2007

A study investigating the influence of a low‐level weir on the diets of three migratory percithyid species was undertaken on the Murrumbidgee River, Australia. A combination of fish community sampling and stomach flushing determined that Yanco Weir substantially impacted upon the abundance and feeding habits of golden perch Macquaria ambigua, Murray cod Maccullochella peelii peelii and trout cod Maccullochella macquariensis. The relative abundance of all three species was significantly greater downstream of the weir, where individuals attempting upstream migrations were obstructed. In areas of fish aggregations, some species displayed altered feeding strategies and exploited different prey taxa upstream and downstream of the weir. Diet overlap, and the proportion of individuals with empty stomachs, was also substantially greater from downstream zones. These results suggest that competition among species may be greater in areas of increased predator abundance and some species could be partitioning resources to minimize competitive interactions. Reducing accumulations of predatory species, by providing suitable fish passage facilities, would be an effective means to prevent such trophic interactions occurring at other low‐level weirs.
Thermal effects on growth and time to starvation during the yolk‐sac larval period of Atlantic mackerel Scomber scombrus L.
Authors: Mendiola D. , Ibaibarriaga L. , Alvarez P.
Published: February 2007

The effect of incubation temperature (8·6, 11·1, 13·2, 15·1 and 16·8° C) on north‐east Atlantic mackerel Scomber scombrus development, growth and age at starvation during the yolk‐sac larval period was investigated. Standard length at hatch was found to be inversely proportional to incubation temperatures within the natural thermal ranges of this species; it ranged from 3·76 mm at 11·1° C to 3·30 mm at 17·8° C. Following hatch, however, larval growth rate was positively related to temperature. Individual logistic models, as a function of temperature and age, were fitted to the development processes of gape, eye pigmentation, jaw mobility and yolk exhaustion. Thereafter, development was classified into different ordered stages and an extended continuation model was fitted to the multinomial ordered stage classification. In all cases, there was a difference of >23 h between the first and the last individual developing in certain stage. The probability of survival decreased with age and was inversely related to temperature. Yolk utilization varied from 4·5 to 8·6 days and individuals died between 7·9 and 12·2 days from 17·8 to 11·1° C. The study demonstrated the significant impact that temperature has on development, growth and survival rates, during the early life history.
Early development and growth of the laboratory reared north‐east Atlantic mackerel Scomber scombrus L.
Authors: Mendiola D. , Alvarez P. , Cotano U. , Martínezde Murguía A.
Published: February 2007

The early development, growth and morphological changes of mackerel Scomber scombrus were investigated at different incubation temperatures (8, 10, 13, 15 and 18° C). Details on the early life history are illustrated with special reference to morphological transformations. Culture techniques to rear larval mackerel stages are described using laboratory cultured foods. Artificially fertilized eggs were hatched after 80·6 h at 18·4° C and 256·8 h at 8·7° C. The standard length (LS) of the individuals at first feeding was 4·71 ± 0·18 mm. Four mortality critical periods and cannibalistic behaviour were identified. A maximum average larval size of 37·5 ± 4·41 mm LS was attained 30 days post‐hatch (dph) at 18·4° C. Development and growth were affected significantly by temperature during both endogenous and exogenous feeding periods. Larvae grew more rapidly at high, than at low temperatures. Daily specific growth rate (in mass) ranged from 2·4% at 10·6° C to 16·9% at 18·4° C. Likewise, average growth rate (in length) ranged from 0·05 mm day−1 at 8·4° C to 0·37 mm day−1 at 18·4° C. The allometric relationship of LS, with several body measurements was not affected by temperature. Comparison with larvae collected in the Bay of Biscay did not show any significant difference in the dry mass and LS relationship; conversely, the growth rate in length differed significantly between both laboratory and field conditions. The trends observed in the laboratory are described in relation to some aspects of the year‐class strength regulation.
A novel immunodeficiency characterized by the exclusive presence of transitional B cells unresponsive to CpG
Authors: Plebani Alessandro , Lougaris Vassilios , Soresina Annarosa , Meini Antonella , Zunino Federica , Losi Claretta Gioia , Gatta Roberta , Cattaneo Gemma , Nespoli Luigi , Marinoni Maddalena , Capolunghi Federica , Vivarelli Marina , Quinti Isabella , Carsetti Rita
Published: February 2007

The objective of this study was to describe a novel form of primary immune disorder characterized by circulating B cells with the exclusive transitional phenotype which fail to respond to CpG stimulation. The 12‐year‐old male patient suffered from recurrent bacterial infections since infancy. The immunological studies were based on extensive B cell immunophenotyping, humoral in vivo response to different vaccine antigens, and in vitro proliferation and immunoglobulin production after CpG stimulation. Sequence analysis for potentially candidate genes such as IRF8, MyD88, TLR9, T‐bet were performed. The patient's serum immunoglobulin levels and the specific antibody response to tetanus toxoid were normal, whereas that to polysaccharide antigens was severely impaired. Flow cytometric analysis showed that almost all patient's peripheral B cells had the transitional phenotype (CD24bright CD38bright CD27neg). Furthermore, the patient's B cells did not proliferate and failed to secrete immunoglobulins after in vitro CpG stimulation. Sequence analysis for TLR9, MyD88, IRF8 and T‐bet showed no mutations. To our knowledge, this is the first case of a novel primary immunodeficiency mimicking the clinical phenotype of common variable immunodeficiency, with a peculiar immunological phenotype characterized by normal immunoglobulin serum levels, circulating B cells with the exclusive transitional phenotype unable to respond to CpG stimulation. This defines a novel form of primary immunodeficiency mimicking common variable immunodeficiency in the presence of normal immunoglobulin serum levels.
CTLA‐4 regulates allergen response by modulating GATA‐3 protein level per cell
Authors: Nasta Francesca , Corinti Silvia , Bonura Angela , Colombo Paolo , Di Felice Gabriella , Pioli Claudio
Published: February 2007

T helper type 2 (Th2) cell differentiation requires the expression of GATA‐3, a transcription factor that allows transcriptional activation of Th2 cytokine genes through chromatin remodelling. We investigated the role of the negative costimulatory receptor cytotoxic T‐lymphocyte antigen 4 (CTLA‐4) in the regulation of GATA‐3 expression, Th2 differentiation and immunoglobulin production during the immune response to allergens. BALB/c mice were immunized with a recombinant major allergenic component of Parietaria judaica pollen, rPar j I, and treated with blocking anti‐CTLA‐4 or control antibodies. Results showed that in vivo CTLA‐4 blockade enhanced the Par j I‐specific immunoglobulin E (IgE) serum level. In contrast, Par j I‐specific IgG2a serum level was reduced, suggesting that CTLA‐4 blockade skewed immunoglobulin production towards interleukin‐4 (IL‐4) ‐dependent immunoglobulin isotypes. Consistently, CTLA‐4 blockade increased the frequency of Par j I‐specific Th2 cells but not Th1 cells, as well as IL‐4 and IL‐5 but not interferon‐γ production. Our data also showed that CTLA‐4 blockade enhanced the GATA‐3 : T‐bet messenger RNA ratio. Interestingly, in vivo CTLA‐4 blockade did not increase the frequency of GATA‐3 protein‐expressing cells. In contrast, it enhances GATA‐3 protein level per cell. Further, in vitro results show that the anti‐CTLA‐4 monoclonal antibody, by competing with CD80 for CTLA‐4 binding, induced an enhancement in the frequency of IL‐4‐producing cells that correlates with the increase in GATA‐3 protein level per cell. In conclusion, CTLA‐4, by affecting the level of GATA‐3 per cell, contributes to keeping this factor under the threshold required to become a Th2 effector cell. Consequently, it affects IgE/IgG2a production and contributes to the outcome of allergen‐specific immune responses.
Immunosenescence: emerging challenges for an ageing population
Authors: Aw Danielle , Silva Alberto B. , Palmer Donald B.
Published: February 2007

It is now becoming apparent that the immune system undergoes age‐associated alterations, which accumulate to produce a progressive deterioration in the ability to respond to infections and to develop immunity after vaccination, both of which are associated with a higher mortality rate in the elderly. Immunosenescence, defined as the changes in the immune system associated with age, has been gathering interest in the scientific and health‐care sectors alike. The rise in its recognition is both pertinent and timely given the increasing average age and the corresponding failure to increase healthy life expectancy. This review attempts to highlight the age‐dependent defects in the innate and adaptive immune systems. While discussing the mechanisms that contribute to immunosenescence, with emphasis on the extrinsic factors, particular attention will be focused on thymic involution. Finally, we illuminate potential therapies that could be employed to help us live a longer, fuller and healthier life.
An improved method for angular‐resolved characterization of the optical anisotropy of pyrolytic carbon
Authors: REZNIK B. , GERTHSEN D. , BORTCHAGOVSKY E.
Published: February 2007

A description is given of an experimental technique that improves the accuracy of the measurement of light extinctions by polarized light microscopy from deposits of pyrolytic carbon. The measurements were performed using a specially developed digital photometric image‐analysis procedure providing high spatial and angular resolution of light extinctions over the reflecting optical domains with a high dynamic range of grey levels. The digital image acquisition and data processing are illustrated using circular‐shaped pyrolytic carbon matrices of infiltrated carbon fibre felts and planar layers of pyrolytic graphite. The calculated value of the extinction angle for single crystalline graphite is discussed with respect to the experimental values for pyrolytic carbon with different degrees of optical anisotropy. Practical requirements for the accuracy of the method are discussed.
Optimized temporal response in multichannel two‐photon fluorescence lifetime microscopy using a photonic crystal fibre
Authors: BIRD D. K. , ELICEIRI K. W. , WHITE J. G.
Published: February 2007

The integration of fibre optics into an imaging system for the convenient delivery and collection of light has resulted in many hybrid forms of novel biomedical optical instrumentation. Although it is extremely robust and cost effective, fibre integration requires special consideration in a time‐domain fluorescence lifetime imaging schema where multipath propagation in the fibre causes significant spread in photon transit times. In this study, we investigated the effect of the length of a multimode collection fibre on the temporal performance of a multichannel fluorescence lifetime microscope and demonstrated the effectiveness of a photonic crystal fibre as a means of optimizing the collection and delivery of emitted fluorescence in terms of temporal resolution. The findings are pertinent to all studies that employ a multimode optical fibre to collect and deliver an emitted fluorescence signal from a sample to a remote detector for measurement of the characteristic fluorescence lifetime.
Transmission electron microscope specimen preparation for exploring the buried interfaces in plan view
Authors: RADNÓCZI G. Z. , PÉCZ B.
Published: February 2007

A relatively easy and convenient process for the preparation of transmission electron microscope specimens of buried interfaces is described. The method is based on the alignment and realignment of the specimen rotation centre during ion milling. The ion‐milling time interval in which good samples are obtained is substantially extended in this way.
Stoichiometry and valence measurements of niobium oxides using electron energy‐loss spectroscopy
Authors: OLSZTA M. J. , WANG J. , DICKEY E. C.
Published: February 2007

Qualitative and quantitative electron energy‐loss spectroscopy analyses have been performed on niobium and stable niobium oxides (NbO, NbO2 and Nb2O5). At integration windows (Δ) greater than 75 eV, k‐factor analysis can be used to distinguish between the stoichiometry of the three oxides within 5.7% error. As seen in other metal oxides, with increasing oxidation state the metal ionization edges shift to higher energies relative to the O‐K edge. Normalized M2,3 white‐line intensities show a strong correlation with 4d occupancy for each compound. The data are in correspondence with that observed in the literature for 4d transition metals using normalized L2,3 white lines. Lastly, a distinctive energy‐loss near‐edge, structure of the O‐K edge was observed for each oxide, which could be used as a fingerprint for analysis of unknowns.
Making sense of nectar scents: the effects of nectar secondary metabolites on floral visitors of Nicotiana attenuata
Authors: Kessler Danny , Baldwin Ian T.
Published: February 2007

Flowers produce a plethora of secondary metabolites but only nectar sugars, floral pigments and headspace volatiles have been examined in the context of pollinator behavior. We identify secondary metabolites in the headspace and nectar of glasshouse‐ and field‐grown Nicotiana attenuata plants, infer within‐flower origins by analyzing six flower parts, and compare the attractiveness of 16 constituents in standardized choice tests with two guilds of natural pollinators (Manducasexta moths and Archilochus alexandri and Selasphorus rufus hummingbirds) and one nectar thief (Solenopsis xyloni ants) to determine whether nectar metabolites can ‘filter’ flower visitors: only two could. Moths responded more strongly than did hummingbirds to headspace presentation of nicotine and benzylacetone, the most abundant repellent and attractant compounds, respectively. For both pollinators, nectar repellents decreased nectaring time and nectar volume removed, but increased visitation number, particularly for hummingbirds. Fewer ants visited if the nectar contained repellents. To determine whether nicotine reduced nectar removal rates in nature, we planted transformed, nicotine‐silenced plants into native populations in Utah over 2 years. Plants completely lacking nicotine in their nectar had 68–70% more nectar removed per night by the native community of floral visitors than did wild‐type plants. We hypothesize that nectar repellents optimize the number of flower visitors per volume of nectar produced, allowing plants to keep their nectar volumes small.
Mala s 12 is a major allergen in patients with atopic eczema and has sequence similarities to the GMC oxidoreductase family*
Authors: Zargari A. , Selander C. , Rasool O. , Ghanem M. , Gadda G. , Crameri R. , Scheynius A.
Published: February 2007

Background:  Atopic eczema (AE) is a chronic inflammatory skin disorder, characterized by impaired skin barrier and itch. The yeast Malassezia belongs to the normal human skin microflora and can induce IgE‐ and T‐cell‐mediated allergic reactions in AE patients. Previously, we have identified several IgE‐binding components in Malassezia sympodialis extract.

Methods:  Here, we report cloning, production and characterization of a M. sympodialis 67‐kDa allergen.

Results:  The sequence of the 67‐kDa protein, termed Mala s 12, showed sequence similarity to the glucose–methanol–choline (GMC) oxidoreductase enzyme superfamily and was expressed as a recombinant protein in Escherichia coli. The purified protein bound flavin adenine dinucleotide with 1:1 stoichiometry per monomer of protein. The protein‐bound flavin showed an extinction coefficient at 451 nm of 11.3 mM−1cm−1. The recombinant 67‐kDa protein did not show any enzymatic activity when tested as oxidase or dehydrogenase using choline, glucose, myo‐inositol, methanol, ethanol, 1‐pentanol, benzyl alcohol, 2‐phenylethanol, cholesterol or lauryl alcohol as possible substrates. Recombinant Mala s 12 was recognized by serum IgE from 13 of 21 (62%) M. sympodialis‐sensitized AE patients indicating that the 67‐kDa component is a major allergen.

Conclusions:  The data show that Mala s 12 has sequence similarity to the GMC oxidoreductase family and is a major allergen in AE patients.
Higher Bcl‐2 levels decrease staphylococcal superantigen‐induced apoptosis of CD4+ T cells in atopic dermatitis
Authors: Lin Y. T. , Wang C. T. , Lee J. H. , Chu C. Y. , Tsao W. C. , Yang Y. H. , Chiang B. L.
Published: February 2007

Background:  Staphylococcal superantigens (SsAgs) contribute to the persistence of allergic skin inflammation in atopic dermatitis (AD). The aims of this study were to (1) determine whether there are differences between AD patients and healthy subjects in SsAg‐induced caspase‐3 activation and SsAg‐induced changes of anti‐apoptotic protein Bcl‐2 and Bcl‐2 mRNA levels of CD4+ T cells; (2) investigate the effect of interleukin (IL)‐4 on SsAg‐induced caspase‐3 activation and SsAg‐induced changes of Bcl‐2 and Bcl‐2 mRNA levels of CD4+ T cells.

Methods:  Using immunofluorescence staining followed by flow cytometric analysis and real‐time PCR, we analyzed peripheral blood mononuclear cells with or without staphylococcal enterotoxin B (SEB) stimulation in the presence or absence of recombinant IL‐4 or anti‐IL‐4 neutralizing antibodies in 16 AD patients and 14 healthy subjects.

Results:  SEB‐reactive (TCRVβ3+, Vβ12+, and Vβ17+) CD4+ T cells from AD patients were more resistant to SEB‐induced caspase‐3 activation and SEB‐induced decrease of Bcl‐2 and Bcl‐2 mRNA than those from healthy subjects. Exogenously added IL‐4 inhibited SEB‐induced caspase‐3 activation and SEB‐induced decrease of Bcl‐2 and Bcl‐2 mRNA in SEB‐reactive CD4+ T cells from healthy subjects. Inhibition of endogenous IL‐4 by using anti‐IL‐4 neutralizing antibodies up‐regulated SEB‐induced caspase‐3 activation and SEB‐induced decrease of Bcl‐2 and Bcl‐2 mRNA in SEB‐reactive CD4+ T cells from AD patients.

Conclusions:  Following SsAg stimulation, IL‐4 produced by T cells in AD patients down‐regulates SsAg‐induced caspase‐3 activation and apoptosis of CD4+ T cells through inhibiting the decrease of Bcl‐2. This may impair deletion of SsAg‐activated T cells and resolution of allergic skin inflammation.
Transcriptional regulation of host enzymes involved in the cleavage of sucrose during arbuscular mycorrhizal symbiosis
Authors: García‐Rodríguez Sonia , Azcón‐Aguilar Concepción , Ferrol Nuria
Published: February 2007

To investigate plant carbon metabolism in arbuscular mycorrhizas, we have analyzed expression of the tomato invertase (EC 3.2.1.26) gene family members and the sucrose synthase (EC 2.4.1.13) gene TOMSSF in roots of non‐mycorrhizal, Glomus mosseae‐ and Glomus intraradices‐colonized plants. Furthermore, root soluble carbohydrate contents have been determined. Gene expression analyses showed that the cell wall invertase Lin6, the vacuolar invertase TIV1 and TOMSSF were upregulated in mycorrhizal roots and that this effect was caused by a direct effect of the colonization by the arbuscular mycorrhizal (AM) fungi and not mediated by an improved phosphorus nutrition. This study shows for the first time upregulation of a cell wall invertase gene in an AM association, which supports the general assumption that carbon transfer across the symbiotic interface requires host sucrose hydrolysis by a cell wall invertase. Transcriptional upregulation of sucrose‐splitting enzymes during early colonization development agrees with the decreased levels of sucrose detected in these roots. Mycorrhizal plants had lower root glucose and fructose concentrations, which indicate consumption of the products of sucrose breakdown. The promoter sequences of Lin6, TIV1 and TOMSSF were analyzed in silico to get insights into the causes of their transcriptional activation in mycorrhizal roots. Upregulation of Lin6, TOMSSF and TIV1 expressions by salicylic acid and of TOMSSF and TIV1 by abscisic acid suggest that these compounds might mediate upregulation of these genes in mycorrhizal roots.
Infectivity variation ofDiscaria trinervis‐nodulatingFrankiain Patagonian soil according to season and storage conditions
Authors: Chaia Eugenia E. , Solans Mariana , Vobis Gernot , Wall Luis G.
Published: February 2007

Changes in the infectious capacity of soilborneFrankiafrom the same site may depend on environmental conditions. To test this, we examined the effect of season of sampling, sample storage protocol and storage time. The nodulation capacity ofFrankiafrom rhizospheric soils ofDiscaria trinervis(Hook et Arn.) Reiche (Rhamnaceae) growing in northwest Patagonia (Argentina) was measured using the most probable number method. Soil samples were collected seasonally and either stored moist at 4°C or air dried at room temperature for few days. Old (air‐dried) soil samples were also assayed. All soils nodulatedD.trinervisseedlings. Nodulation units (NU) ranged from 44 (spring, moist storage) to about 1 ml−1of soil (summer moist, and summer and autumn, air‐dried storage), with intermediate values in other samples. Soils stored for 12 years, 6 months or 1 week had similar NU.FrankiaNU positively correlated with soil water content (r= 0.6,P< 0.05); therefore, it is likely that soil moisture is a relevant factor regulating soilborneFrankianodulation ability in Patagonian soils. We suggest thatFrankiacan remain as spores or grow saprophytically in Patagonian soils.
The effects on the lower esophageal sphincter of sevoflurane induction and increased intra‐abdominal pressure during laparoscopy
Authors: Thörn K. , Thörn S.‐E. , Wattwil M.
Published: February 2007

Background:  Today sevoflurane is one of the most frequently used volatile anesthetics. The speed of induction can approach that of intravenous anesthetics, and case reports using sevoflurane induction for emergency anesthesia have been published. The purpose of this study in laparoscopic cholecystectomy patients was to investigate the effects of sevoflurane during inhalation induction on the lower esophageal sphincter pressure (LESP) and barrier pressure (BrP). The effects on lower esophageal sphincter (LES) and BrP of increased intra‐abdominal pressure during laparoscopy were also evaluated.

Methods:  We recorded LESP and BrP in nine patients using a Dent sleeve device. Recordings were made before and after inhalation induction of anesthesia with 8% sevoflurane, as well as before and after insufflation of CO2 into the abdomen.

Results:  After induction with sevoflurane, LESP (P= 0.039) and BrP (P= 0.020) decreased. Nevertheless, BrP was kept positive in all patients. Insufflation of CO2 into the abdomen during laparoscopy induced a significant increase in LESP (P= 0.02) and gastric pressure (P= 0.004). However, there was no significant change in BrP (P= 0.66); it increased in four patients and decreased in five.

Conclusion:  BrP was kept positive in all patients after induction of anesthesia. Therefore, we believe that in combination with cricoid pressure, inhalation induction with sevoflurane might be a safe choice. As the adaptive increase in LESP during laparoscopy was not enough to retain a barrier pressure in all patients, it is important to be aware of the risk of regurgitation throughout the anesthesia.
Transfusion vs. alternative treatment modalities in acute bleeding: a systematic review
Authors: Heier H. E. , Bugge W. , Hjelmeland K. , Søreide E. , Sørlie D. , Håheim L. L.
Published: February 2007

Background and methods:  The practice of transfusion varies a great deal between countries and hospitals. Therefore, a systematic literature review was performed to evaluate the evidence underlying practice of transfusion and alternative treatment modalities in acute bleeding. After a stepwise evaluation, 79 out of 2438 abstracts were approved as the evidence base.

Results:  Albumin for volume therapy is not better than artificial colloids or crystalloids and may be detrimental in trauma patients. No outcome difference has been proved between artificial colloids and crystalloids. Use of hypertonic solutions remains controversial, as do the concepts of delayed and hypotensive resuscitation. Healthy individuals tolerate acute, normovolaemic anaemia at 5 g haemoglobin/dl, but pre‐operative haemoglobin < 6 g/dl gives increased mortality from surgical interventions. Keeping haemoglobin higher than 8–9 g/dl has not been associated with any positive effect on mortality or morbidity, even in patients with cardiovascular disease. The changes induced in erythrocytes by storage may be clinically insignificant. No alternative to erythrocyte transfusion was established. Evidence underlying the practice of thrombocyte and plasma transfusion is scarce. Available evidence on recombinant coagulation factor VIIa is insufficient to define its future role in acute bleedings. Antifibrinolytic drugs in general seem to reduce the need for transfusion.

Conclusions:  Intravenous volume replacement and transfusion policies seem largely based on local tradition and expert opinions. As a result of the difficulties in performing controlled studies in patients with acute bleeding and the large number of patients needed to prove effects, other scientific evidence should be sought to better define best practice in this important field.
Anti‐inflammatory effect of high‐dose insulin treatment after urgent coronary revascularization surgery
Authors: Koskenkari J. K. , Kaukoranta P. K. , Rimpiläinen J. , Vainionpää V. , Ohtonen P. P. , Surcel H.‐M. , Juvonen T. , Ala‐Kokko T. I.
Published: February 2007

Background:  The administration of insulin has been shown to exert cardioprotective and immunomodulatory properties. Ischemia and inflammation are typical features of acute coronary syndrome, thus it was hypothesized that high‐dose glucose–insulin–potassium (GIK) treatment could suppress the systemic inflammatory reaction and attenuate myocardial ischemia–reperfusion injury in patients with unstable angina pectoris after urgent coronary artery bypass surgery.

Methods:  Forty patients with unstable angina pectoris scheduled for urgent coronary artery bypass surgery and cardiopulmonary bypass were randomly assigned to receive either high‐dose insulin treatment (short‐acting insulin 1 IU/kg/h with 30% glucose 1.5 ml/kg/h administered separately) or control treatment (saline). Blood glucose levels were targeted to 6.0–8.0 mmol/l in both groups by adjusting the rate of glucose infusion in the GIK group and by additional insulin in the control group as needed.

Results:  High‐dose insulin treatment was associated with significantly lower average C‐reactive protein (23.8 vs. 40.1 mg/l, P= 0.008) and free fatty acid levels (0.22 vs. 0.41 mmol/l, P= < 0.001) post‐operatively. Average blood glucose levels were comparable during the intensive care unit (ICU) stay (7.1 vs. 6.9 mmol/l, P= 0.5) and 95% of the control patients received supplemental insulin. The pro‐inflammatory cytokine response [interleukin‐6 (IL‐6), interleukin‐8 (IL‐8) and tumor necrosis factor‐α (TNF‐α)] did not differ between the groups and beneficial effects on myocardial injury were not detected.

Conclusions:  High‐dose insulin treatment has potential anti‐inflammatory properties independent of its ability to lower blood glucose levels. Even profound suppression of free fatty acid levels, the attenuation of myocardial ischemia–reperfusion injury was not detected.
Does Host Value Influence Female Aggressiveness, Contest Outcome and Fitness Gain in Parasitoids?
Authors: Goubault Marlene , Cortesero Anne Marie , Poinsot Denis , Wajnberg Eric , Boivin Guy
Published: February 2007

Intraspecific competition for resources is common in animals and may lead to physical contests. Contest outcomes and aggressiveness can be influenced by the resource holding potential of contestants but also by their perception of the resource value (RV). Competitors may assess resource quality directly (real RV) but may also estimate it according to their physiological status and their experience of the habitat quality (subjective RV). In this article, we studied contests between females of the solitary parasitoidPachycrepoideus vindemmiaeRondani (Hymenoptera: Pteromalidae) when exploiting simultaneously a host, aDelia radicumL. (Diptera: Anthomyiidae) pupa. We tested the effect of factors modifying host value on the occurrence of agonistic behaviours, contest outcomes and host exploitation. The factors tested were: the quality of the previous habitat experienced by females, female egg load, host parasitism status and the stage reached by the owner female in her behavioural oviposition sequence. Females successfully protected their host against intruders during its exploitation, but not after oviposition, and their aggressiveness did not seem to be influenced by their perception of the RV. The fact that the host is subsequently parasitized by the opponent females appears to mainly depend on the host selectiveness of females.
Germination of Salicornia bigelovii Ecotypes under Stressing Conditions of Temperature and Salinity and Ameliorative Effects of Plant Growth‐promoting Bacteria
Authors: Rueda‐Puente E. O. , García‐Hernández J. L. , Preciado‐Rangel P. , Murillo‐Amador B. , Tarazón‐Herrera M. A. , Flores‐Hernández A. , Holguin‐Peña J. , Aybar A. N. , Barrón Hoyos J. M. , Weimers D. , Mwandemele O. , Kaaya G. , Mayoral J. L. , Troyo‐Diéguez E.
Published: February 2007

Salinity is a major stress condition. Salicornia bigelovii is a valuable edible halophyte, considered to be a promising resource for cultivation in arid coastal zones. Its productivity depends on the supplementary provision of nitrogen, for which an option is chemical fertilization. Nevertheless, indiscriminate use of chemical fertilizers contributes to the problem of increased salinity. The inoculation of plant growth‐promoting bacteria (PGPB) represents an alternative. Seed ecotypes from four coastal areas [Santa Rosa Chica, Santa Rosa Grande, Santa Cruz and Cerro Prieto (CP), Sonora, México] were collected, in order to inoculate them with two species of PGPB (Azospirillum halopraeferens and Klebsiella pneumoniae). Two germination tests were carried out to study the effect of salinity, temperature regime (night/day) and inoculation with PGPB on germination (percentage and rate), plant height, root length and biomass produced (fresh and dry matter). In the first test, all four ecotypes were considered, whereas in the second test only the CP ecotype was involved because it was found to be the outstanding ecotype in the previous test. Results showed inhibition of germination when salinity was higher in all ecotypes except CP. The CP ecotype showed a decrease of seed germination with an increase in NaCl concentrations at all temperatures tested. However, when it was inoculated with both PGPB, the germination percentage was influenced.
Evolution and the latitudinal diversity gradient: speciation, extinction and biogeography
Authors: Mittelbach Gary G. , Schemske Douglas W. , Cornell Howard V. , Allen Andrew P. , Brown Jonathan M. , Bush Mark B. , Harrison Susan P. , Hurlbert Allen H. , Knowlton Nancy , Lessios Harilaos A. , McCain Christy M. , McCune Amy R. , McDade Lucinda A. , McPeek Mark A. , Near Thomas J. , Price Trevor D. , Ricklefs Robert E. , Roy Kaustuv , Sax Dov F. , Schluter Dolph , Sobel James M. , Turelli Michael
Published: February 2007

A latitudinal gradient in biodiversity has existed since before the time of the dinosaurs, yet how and why this gradient arose remains unresolved. Here we review two major hypotheses for the origin of the latitudinal diversity gradient. The time and area hypothesis holds that tropical climates are older and historically larger, allowing more opportunity for diversification. This hypothesis is supported by observations that temperate taxa are often younger than, and nested within, tropical taxa, and that diversity is positively correlated with the age and area of geographical regions. The diversification rate hypothesis holds that tropical regions diversify faster due to higher rates of speciation (caused by increased opportunities for the evolution of reproductive isolation, or faster molecular evolution, or the increased importance of biotic interactions), or due to lower extinction rates. There is phylogenetic evidence for higher rates of diversification in tropical clades, and palaeontological data demonstrate higher rates of origination for tropical taxa, but mixed evidence for latitudinal differences in extinction rates. Studies of latitudinal variation in incipient speciation also suggest faster speciation in the tropics. Distinguishing the roles of history, speciation and extinction in the origin of the latitudinal gradient represents a major challenge to future research.
Timing, segmental status and aspiration in icelandic
Authors: Lodge Ken
Published: February 2007

This paper questions the a priori assumption of the segment in phonology by considering the issues surrounding the relative timing of articulatory movements and its relationship with phonological structure. The specific focus of the paper is on pre‐ and postaspiration in Icelandic, with a question as to why the former is normally treated as segmental while the latter is not. An alternative analysis is offered which does not assume cross‐parametric slicing into segments, which is declarative rather than derivational, and which is polysytemic as opposed to monosystemic. Timing is located in the phonetic implementation component of the phonology, which is language‐specific rather than universal.