bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple metabolic signals influence GAL gene activation by modulating the interaction of Gal80p with the transcriptional activator Gal4p
Authors: Li Yan , Chen Guanjun , Liu Weifeng 
Published: August 2010

SummaryTranscriptional status of the genes needed for galactose utilization in Saccharomyces cerevisiae is controlled by the interplay between the prototypical transcriptional activator Gal4p and the inhibitor protein Gal80p. Relief of the inhibition from Gal4p requires the interaction between Gal80p and the galactokinase paralog, Gal3p. Here, we present evidence that decrease in the intracellular levels of ATP or NADP(H) impairs the GAL gene expression. All these induction defects are rescued by overproducing Gal3p or producing Gal4p mutants with reduced interaction with Gal80p. We further demonstrate that removal of Gal80p from the GAL gene promoter is impaired in these mutants, and that NADP(H) cooperates with Gal3p in causing the dissociation of Gal80p from the in vitro preformed DNA‐bound Gal80p–Gal4p complex. We also show that Gal80p is only partially removed from the GAL gene promoter in a mitochondria fusion‐deficient mutant where the cotranscriptional mRNA processing is crippled. The efficient dissociation is restored by Gal4p mutants with altered interaction with Gal80p and is correlated with the recovered GAL gene expression. These results indicate that multiple metabolic signals exist to facilitate the efficient and appropriate dissociation of Gal80p from Gal4p by Gal3p to achieve the fully active state of Gal4p in the nucleus.
Membrane association of PspA depends on activation of the phage‐shock‐protein response in Yersinia enterocolitica
Authors: Yamaguchi Saori , Gueguen Erwan , Horstman N. Kaye , Darwin Andrew J. 
Published: August 2010

SummaryRegulation of the bacterial phage‐shock‐protein (Psp) system involves communication between integral (PspBC) and peripheral (PspA) cytoplasmic membrane proteins and a soluble transcriptional activator (PspF). In this study protein subcellular localization studies were used to distinguish between spatial models for this putative signal transduction pathway in Yersinia enterocolitica. In non‐inducing conditions PspA and PspF were almost exclusively in the soluble fraction, consistent with them forming an inhibitory complex in the cytoplasm. However, upon induction PspA, but not PspF, mainly associated with the membrane fraction. This membrane association was dependent on PspBC but independent of increased PspA concentration. Analysis of psp null, overexpression and altered function mutants further supported a model where PspA is predominantly membrane associated only when the system is induced. Activation of the Psp system normally leads to a large increase in PspA concentration and we found that this provided a second mechanism for its membrane association, which did not require PspBC. These data suggest that basal PspFABC protein levels constitute a regulatory switch that moves some PspA to the membrane when an inducing trigger is encountered. Once this switch is activated PspA concentration increases, which might then allow it to directly contact the membrane for its physiological function.
Repeat regions R1 and R2 in the P97 paralogue Mhp271 ofMycoplasma hyopneumoniaebind heparin, fibronectin and porcine cilia
Authors: Deutscher Ania T. , Jenkins Cheryl , Minion F. Chris , Seymour Lisa M. , Padula Matthew P. , Dixon Nicholas E. , Walker Mark J. , Djordjevic Steven P. 
Published: August 2010

SummaryMycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, adheres to ciliated respiratory epithelia resulting in ciliostasis and epithelial cell death. The cilium adhesin P97 (Mhp183) contains two repeat regions, designated R1 and R2, that play key roles in adherence. Eight pentapeptide repeats in R1 are sufficient to bind porcine cilia; however, both R1 and R2 are needed to bind heparin. Mhp271, a paralogue of P97, is the only otherM. hyopneumoniaeprotein to contain both R1 and R2 repeats. These repeats are arranged as a set of three pentapeptide repeats (designated R1A271), two decapeptide repeats (designated R2271), and a second set of six pentapeptide repeats (designated R1B271). To determine their function, recombinant proteins containing R1A271(F1271) and R2271‐R1B271(F2271) were constructed and used inin vitrobinding assays. F2271, but not F1271, bound heparin (KD = 8.1 ± 0.4 nM), fibronectin (KD = 174 ± 13 nM) and porcine cilia. Pre‐incubation of F2271with 100 µM heparin blocked cilium binding by ∼69%. Cell surface shaving with trypsin combined with two‐dimensional liquid chromatography coupled to tandem mass spectrometry analysis identified Mhp271 as surface‐exposed. Our data suggest that both R1 and R2 in Mhp271 are involved in binding to host molecules.
Environmental control of phosphorylation pathways in a branched two‐component system
Authors: López‐Redondo Maria Luisa , Moronta Felix , Salinas Paloma , Espinosa Javier , Cantos Raquel , Dixon Ray , Marina Alberto , Contreras Asunción 
Published: August 2010

SummaryNblS, the most conserved histidine kinase in cyanobacteria, regulates photosynthesis and acclimatization to a variety of environmental conditions. We used in silico, in vivo and in vitro approaches to identify RpaB and SrrA as the cognate response regulators of NblS and to characterize relevant interactions between components of this signalling system. While genetic analysis showed the importance of the NblS to RpaB phosphorylation branch for culture viability in Synechococcus elongatus PCC 7942, in vitro assays indicated a strong preference for NblS to phosphorylate SrrA. This apparent discrepancy can be explained by environmental insulation of the RpaB pathway, achieved by RpaB‐dependent repression of srrA under standard, low light culture conditions. After a strong but transient increase in srrA expression upon high light exposure, negative regulation of srrA and other high light inducible genes takes place, suggesting cooperation between pathways under environmental conditions in which both RpaB and SrrA are present. Complex regulatory interactions between RpaB and SrrA, two response regulators with a common evolutionary origin that are controlled by a single histidine kinase, are thus emerging. Our results provide a paradigm for regulatory interactions between response regulators in a branched two‐component system.
Complete resolution of psoriasis vulgaris after excision of thyroid cancer
Authors: Kano Yoko , Chiba Masako , Yagita Akikuni , Shiohara Tetsuo 
Published: August 2010

A 61‐year‐old woman was seen with a 1‐month history of a widespread eruption over the trunk and extremities. She also had an asymptomatic tumor in the neck that had developed 8 years earlier. Examination revealed generalized, erythematous scaling plaques over the trunk, arms, and extremities (Fig. 1). An ultrasound and radioisotope scan of the neck disclosed a soft tissue mass compatible with thyroid carcinoma.Laboratory tests showed a white cell count of 9.8X109/L, and triiodothyronine, thyroxin, and calcium levels within the normal range. The thyroid‐stimulating hormone (TSH) level was 6.3 μIU/mL (normal range 0.33–3.6 μIU/mL), and thyroglobulin was 320 μg/mL (normal range 14–31 μg/mL).A skin biopsy specimen from the upper portion of the arm showed hyperkeratosis with focal parakeratosis and elongation of the rete ridges. The dermis showed mild papillary edema and perivascular lymphocytic infiltration compatible with psoriasis vulgaris. After the biopsy, ampicillin, 1000 mg daily, was administered for 21 days; however, the lesions were unchanged. The patient was then operated on with excision of the thyroid cancer and the regional lymph nodes. Histopathologic examination disclosed an adenocarcinoma of the thyroid; the lymph nodes were infiltrated by tumor cells. After the operation, cefazolin, 2000 mg daily, was given for 9 days. At 2 weeks postoperatively, the lesions began to subside without any dermatologic treatment and then resolved completely within 1 month of the operation (Fig. 2). Three weeks after the excision of the tumor, the patient started to receive levothyroxine sodium (T4), 0.1 mg daily, to compensate for low thyroid hormone production. Within the second postoperative month, TSH, triiodothyronine, and thyroglobulin returned to normal. After excision of the carcinoma, her psoriatic lesions, remained in remission for an additional 5 months without any dermatologic treatment.
Immediate and 5‐year cumulative outcome after paediatric intensive care in Sweden
Authors: GULLBERG N. , KALZÉN H. , LUHR O. , GÖTHBERG S. , WINSÖ O. , MARKSTRÖm A. , OLSSON A.‐K. , FROSTELL C. ,   SCANDINAVIAN CRITICAL CARE TRIALS GROUP
Published: August 2010

Background: Little has been reported about intensive care of children in Sweden. The aims of this study are to (I) assess the number of admissions, types of diagnoses and length‐of‐stay (LOS) for all Swedish children admitted to intensive care during the years 1998–2001, and compare paediatric intensive care units (PICUs) with other intensive care units (adult ICUs) (II) assess immediate (ICU) and cumulative 5‐year mortality and (III) determine the actual consumption of paediatric intensive care for the defined age group in Sweden.Methods: Children between 6 months and 16 years of age admitted to intensive care in Sweden were included in a national multicentre, ambidirectional cohort study. In PICUs, data were also collected for infants aged 1–6 months. Survival data were retrieved from the National Files of Registration, 5 years after admission.Results: Eight‐thousand sixty‐three admissions for a total of 6661 patients were identified, corresponding to an admission rate of 1.59/1000 children per year. Median LOS was 1 day. ICU mortality was 2.1% and cumulative 5‐year mortality rate was 5.6%. Forty‐four per cent of all admissions were to a PICU.Conclusions: This study has shown that Sweden has a low immediate ICU mortality, similar in adult ICU and PICU. Patients discharged alive from an ICU had a 20‐fold increased mortality risk, compared with a control cohort for the 5‐year period. Less than half of the paediatric patients admitted for intensive care in Sweden were cared for in a PICU. Studies are needed to evaluate whether a centralization of paediatric intensive care in Sweden would be beneficial to the paediatric population.
The effects of sheep grazing on invertebrate numbers and biomass in unfertilized natural pastures of the New England Tablelands (NSW)
Authors: KING KATHLEEN L. , HUTCHINSON KEITH J. 
Published: August 2010

AbstractInvertebrate components of natural pastures which were grazed continuously by sheep at three stocking intensities, were sampled each season for more than two years. Grazing resulted in a significant reduction in abundance of litter and topsoil micro‐arthropods. Two samplings for nematodes and enchytraeids showed similar reductions with grazing. Grazing effects on the vertical distribution of mesofauna were not consistent but all sites had greatest numbers in the 0 – 5 cm topmost soil layer. Fresh biomass of large soil and litter dwelling invertebrates also declined with grazing, with proportionally greater reductions occurring for litter animals. Changes in invertebrate populations were associated with changes in living space, microclimate and food supply. Populations of invertebrates on natural pastures were about one‐third those found on previously studied sown, fertilized pastures at Armidale.
Annuals with transient seed banks: the population biology of indigenous Sorghum species of tropical north‐west Australia
Authors: ANDREW MARTIN H. , MOTT JOHN J. 
Published: August 2010

AbstractIndigenous Sorghum species are a prominent feature of the seasonally‐dry tropics of north‐west Australia. Studies of the dormancy characteristics of these species were undertaken, and measurements of seedling emergence, of plant survival, growth and reproductive success, and of seed bank changes were made for one Sorghum intrans population and for three S. stipoideum populations over two growing seasons.On wetting, 90% of the non‐dormant, viable seeds of nil species germinated within five days. The temperature range for optimal germination was 25 ‐ 35°C, and germination declined with decreasing water potential. The seeds of all species had high innate dormancy at seedfall, and this was broken down over the ensuing dry season.For S. intrans and S. stipoideum height and tiller number increased steadily after emergence up to the time of floral initiation, which occurred simultaneously for primary tillers within each population. Most vegetative tillers died after this leaving a single reproductive culm which rapidly elongated to reach 1 – 4 mat maturity, depending on site and season.Seedfall occurred over a short, c. two‐week period before the rainy season had finished. Seeds were dispersed within 2 m of the parent plant. Seeds were buried to less than 2 cm by the screwing action of their hygroscopically‐active awns.All these annual Sorghum species appear to have transient seedbanks, formed at seedfall near the end of one rainy season and exhausted by germination following the first rains of the next annual rainy season. We suggest that S. intrans and S. stipoideum persist despite this feature because they mature at the earliest time that the rainy season has been known to end in their respective localities. Persistence is further aided by adaptations which enable individuals to survive the unpredictable short droughts which occur while they are emerging and growing. S. intrans and S. stipoideum have low fecundity (mean ≃ 8 viable seeds per individual) and high survivorship. They fit Watkinson's (1981) schema relating fecundity to survival for annuals with transient seed banks.
Suburban development and change in vegetation nutritional status
Authors: LAMBERT MARCIA J. , TURNER JOHN 
Published: August 2010

AbstractIn a study of species presence/absence and soil properties in bushland around northern Sydney, Clements (1983) found that species groupings were related to total soil phosphorus. This report presents analysis of foliage nutrient concentrations in species within these groupings. The highest concentrations of phosphorus, calcium, magnesium and potassium occurred in the suburban/disturbed group. The lowest overall concentrations were found in foliage from species in the dry sclerophyll communities. Mean foliage phosphorus was 0.099%, 0.125% and 0.042% for wet sclerophyll, disturbed and dry sclerophyll groups, respectively. Exotic species, particularly in disturbed environments, had the highest foliage nutrient concentrations. Results presented here showed that foliage nutrient concentrations are consistent with definitions of these groups on the basis of total soil phosphorus. These changes are considered to be important for management and conservation of bushland areas around Sydney.
The seasonal abundance and foraging behaviour of honeyeaters and their potential role in the pollination ofBanksia menziesii
Authors: RAMSAY M. W. 
Published: August 2010

AbstractSeasonal changes in the abundances of five species of honey‐eaters were assessed in relation to the flowering phenology of Banksia menziesii in banksia woodland near Perth, Western Australia. The total number of honeyeaters was significantly correlated to the number of inflorescences ofB. menziesii. New Holland Honeyeaters. Brown Honeyeaters and Western Spinebills were present throughout the year, whereas the larger honeyeaters (Red and Little Wattlebirds) were observed when B. menziesii was flowering.The foraging behaviours of the Little Wattlebirds, New Holland Honeyeaters, Brown Honeyeaters and Western Spinebills were similar and all were likely to effect pollination of B. menziesii florets. Differences in their foraging position at an inflorescence, number and direction of foraging probes, and the time spent at an inflorescence were minimal. Western Spinebills used inflorescences lower in the tree crown than the other species. Movements to inflorescences on different plants were inversely related to honeyeater size. Smaller honeyeaters were frequently chased from inflorescences by the larger species, increasing the proportion of distant foraging movements made by the smaller species. Also these interrupted visits were of shorter duration than uninterrupted visits. Visitation by smaller species, especially the Brown Honeyeater, may result in more cross pollinations although the effect on the reproductive success of B, menziesii is unknown.
Movement and modelling of buried seed of the invasive perennial Chrysanthemoides monilifera in coastal dunes and biological control
Authors: NOBLE I. R. , WEISS P. W. 
Published: August 2010

AbstractMovement in the soil of seeds of the invasive shrub Chrysanthemoides monilifera was studied in relation to the success of proposed biological control treatments. Marked seeds were buried at depths from 0 to 6 cm and recovered after periods of 3–24 months. Survival declined with time but was higher for more deeply buried seeds. The average movement of seeds was 0.7 cm per year downwards which enhances their survival but also tends to remove them from the zone of highest likelihood of germination.A model was constructed to predict the size of the pool of potentially germinable seed under treatments including pre‐dispersal predation and burning. It indicated that satisfactory control with a pre‐dispersal seed predator will be achieved only if there is a < 95% reduction in seed‐fall to the soil surface over the entire year. A control agent that is 100% effective for most of the year will probably be unsatisfactory if its rate of predation drops to > 90% for a part of the year (e.g. during winter when seed‐fall is abundant). The effectiveness of the control could be enhanced by using intense fires to reduce the soil seed‐pool and to kill many of the mature shrubs. However, the feasibility of this combination of treatments will depend on the reaction of the biological control agent to fire.
Patterns of bird species richness and composition on islands off Arnhem Land, Northern Territory, Australia
Authors: Woinarski J. C. Z. , Fisher A. , Brennan K. , Morris I. , Chatto R. 
Published: August 2010

AbstractThe bird faunas of the adjacent Wessel and English Company island chains were sampled at two scales (0.25 ha quadrats and entire islands). Ninety‐six species were recorded from 226 quadrats, with the most frequently recorded species being mistletoebird Dicaeum hirundinaceum, brown honeyeater Lichmera indistincta, silver‐crowned friarbird Philemon argenticeps, bar‐shouldered dove Geopelia humeralis, northern fantail Rhipidura rufiventris and yellow white‐eye Zosterops lutea. At the quadrat scale, vegetation type was a major determinant of the abundance of individual species (and hence species composition), species richness and total bird abundance. Bird species composition and richness at the quadrat scale was also significantly affected by island isolation (particularly the amount of land within 20 km of the island perimeter). Island size had no effect on quadrat‐scale richness or total abundance. However, the abundance of 10 of the 38 most frequently recorded individual species was significantly related to island size, in most cases even when the comparison was restricted to similar habitats. The most striking cases were rufous fantail Rhipidura rufifrons, mangrove golden whistler Pachycephala melanura, brown honeyeater and yellow white‐eye, which were all significantly more abundant on smaller islands. One hundred and seventy‐one species were recorded from the 62 islands sampled. There was a very tight relationship between island size and the number of terrestrial species (73% of deviance explained) and of all species (84% of deviance explained). This relationship was improved (marginally) when isolation was included in the model. Ordination of islands by their terrestrial bird species composition was related to island size and isolation, and suggested an erratic species composition on small islands.
Territory acquisition in a polymorphic lizard: An experimental approach
Authors: HEALEY M. , OLSSON M. 
Published: August 2010

AbstractMales of the colour polymorphic Australian painted dragon lizard Ctenophorus pictus occur in red or yellow head colouration. In a previous experiment, we showed that red is associated with a higher probability of winning staged contests for resources (females or space) and that manipulation of male colouration by painting males in the opposing morph changed the dynamics of staged interactions by prolonging them 30‐fold. Thus, colour is linked to behavioural differences between males and is involved in information transfer between competing males. This inherent red dominance could result in yellow males being marginalized to poorer quality territories in terms of access to females, food, perch sites or shade. With an experiment in the wild, we test to what extent this prediction is upheld, and how colour manipulation affects morph‐specific success in territory acquisition when male body size, territory quality and emergence time from hibernation are controlled through manipulation or randomization. There was no significant effect of colour category per se, although on average red males remained closer to the release sites (our proxy for territory acquisition ability) than yellow males and artificially altered morphs moved the furthest away. There was a significant interaction effect between colour category and experimental release position, which may be linked to differences in how exposed (or not) these positions were and morph‐specific ability to cope with such exposure (e.g. ‘boldness’). Our data show that territory acquisition success is not merely a function of competitive ability but a composite outcome of a suite of factors, including signal perception.
The habitat requirements of four sympatric rock‐dwelling macropods of the Australian monsoon tropics
Authors: TELFER WENDY R. , GRIFFITHS ANTHONY D. , BOWMAN DAVID M. J. S. 
Published: August 2010

AbstractA high diversity of rock‐dwelling macropod species inhabit the tropics of the Northern Territory, Australia. Within this region, individual species have varied distributions, with ranges variously being widespread, restricted, or geographically disjunct with variable levels of sympatry between them. The cause of these patterns is unknown and little is known of the ecology of these rock‐dwelling macropods. We hypothesized that differences in the habitat requirements is the key to understanding the biogeography and sympatry of the species. We examined this hypothesis at both regional and local scales. We analysed records of occurence of Petrogale brachyotis, P. concinna, Macropus bernardus and M. robustus and environmental correlates (such as geology type, vegetation type, distance to drainage and distance to ‘rugged’ terrain) throughout the monsoon tropics using geographic information systems and generalized linear modelling. We surveyed 80 sites across the tropics of the Northern Territory and collected presence‐absence data using scats and environmental correlates to examine fine‐scale habitat requirements. From the regional scale analysis, it was clear that distance to rugged terrain strongly influences presence of all four species. Responses to this variable suggest M. bernardus and P. concinna have greater requirements for rugged terrain, whereas M. robustus and P. brachyotis are found across a broader range of habitats. The local scale analysis suggested presence of M. robustus is primarily driven by vegetation type, M. bernardus by the cover of outcrops, boulders and large rocks, and P. brachyotis by the density of caves. Although these species overlap in their use of habitats, there are also differences in their habitat requirements that are likely to play a role in their niche separation and in some cases their biogeography. However, it is apparent that the distributions of the species have also been influenced by historical factors given the absence of these species from some apparently suitable sites.