bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Heat Shock Response in Moss Plants Is Regulated by Specific Calcium-Permeable Channels in the Plasma Membrane
Authors: Saidi Younousse , Finka Andrija , Muriset Maude , Bromberg Zohar , Weiss Yoram G. , Maathuis Frans J.M. , Goloubinoff Pierre 
Published: September 2009

AbstractLand plants are prone to strong thermal variations and must therefore sense early moderate temperature increments to induce appropriate cellular defenses, such as molecular chaperones, in anticipation of upcoming noxious temperatures. To investigate how plants perceive mild changes in ambient temperature, we monitored in recombinant lines of the moss Physcomitrella patens the activation of a heat-inducible promoter, the integrity of a thermolabile enzyme, and the fluctuations of cytoplasmic calcium. Mild temperature increments, or isothermal treatments with membrane fluidizers or Hsp90 inhibitors, induced a heat shock response (HSR) that critically depended on a preceding Ca2+ transient through the plasma membrane. Electrophysiological experiments revealed the presence of a Ca2+-permeable channel in the plasma membrane that is transiently activated by mild temperature increments or chemical perturbations of membrane fluidity. The amplitude of the Ca2+ influx during the first minutes of a temperature stress modulated the intensity of the HSR, and Ca2+ channel blockers prevented HSR and the onset of thermotolerance. Our data suggest that early sensing of mild temperature increments occurs at the plasma membrane of plant cells independently from cytosolic protein unfolding. The heat signal is translated into an effective HSR by way of a specific membrane-regulated Ca2+ influx, leading to thermotolerance.
Autophagy Negatively Regulates Cell Death by Controlling NPR1-Dependent Salicylic Acid Signaling during Senescence and the Innate Immune Response inArabidopsis
Authors: Yoshimoto Kohki , Jikumaru Yusuke , Kamiya Yuji , Kusano Miyako , Consonni Chiara , Panstruga Ralph , Ohsumi Yoshinori , Shirasu Ken 
Published: September 2009

AbstractAutophagy is an evolutionarily conserved intracellular process for vacuolar degradation of cytoplasmic components. In higher plants, autophagy defects result in early senescence and excessive immunity-related programmed cell death (PCD) irrespective of nutrient conditions; however, the mechanisms by which cells die in the absence of autophagy have been unclear. Here, we demonstrate a conserved requirement for salicylic acid (SA) signaling for these phenomena in autophagy-defective mutants (atg mutants). The atg mutant phenotypes of accelerated PCD in senescence and immunity are SA signaling dependent but do not require intact jasmonic acid or ethylene signaling pathways. Application of an SA agonist induces the senescence/cell death phenotype in SA-deficient atg mutants but not in atg npr1 plants, suggesting that the cell death phenotypes in the atg mutants are dependent on the SA signal transducer NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1. We also show that autophagy is induced by the SA agonist. These findings imply that plant autophagy operates a novel negative feedback loop modulating SA signaling to negatively regulate senescence and immunity-related PCD.
Germ‐line mutation of the NRAS gene may be responsible for the development of juvenile myelomonocytic leukaemia
Authors: De Filippi Paola , Zecca Marco , Lisini Daniela , Rosti Vittorio , Cagioni Claudia , Carlo‐Stella Carmelo , Radi Orietta , Veggiotti Pierangelo , Mastronuzzi Angela , Acquaviva Antonio , D’Ambrosio Alfonso , Locatelli Franco , Danesino Cesare 
Published: September 2009

SummaryWe report the case of a child with clinical and haematological features indicative of juvenile myelomonocytic leukaemia (JMML). The patient showed dysmorphic features: high forehead, bilateral epicanthal folds, long eyebrows, low nasal bridge and slightly low‐set ears. A 38G>A (G13D) mutation in exon 1 of the NRAS gene was first demonstrated on peripheral blood cells, and then confirmed on granulocyte‐macrophage colony‐forming units. The same mutation was also found in buccal swab, hair bulbs, endothelial cells, skin fibroblasts. This case suggests for the first time that constitutional mutations of NRAS may be responsible for development of a myeloproliferative/myelodysplastic disorder in children.
Bone mass acquisition in female rhythmic gymnasts during puberty: no direct role for leptin
Authors: Maïmoun Laurent , Coste Olivier , Jaussent Audrey , Mariano‐Goulart Denis , Sultan Charles , Paris Françoise 
Published: September 2009

SummaryObjectives  Although hypoleptinaemia has been reported in female peripubertal athletes, data are lacking on leptin and bone mass variations in puberty and the effects of leptin on bone mineralization during this period. This study therefore investigated the variations in leptin level and bone mineral density (BMD) in young elite female rhythmic gymnasts (FRG) according to pubertal stage. The effects of leptin, IGF‐1 and sex hormones on bone mineral acquisition were also evaluated.Patients and measurements  Plasma leptin levels were analysed in 43 elite FRG (mean age: 13·3 ± 1·8 years range: 10·6–17·2, body mass index: 17·52 ± 1·85 kg/m², training status: 17·9‐23·8 h/week) according to their pubertal stage (Tanner I, n = 7; II, n = 10; III, n = 9; IV, n = 8; V, n = 9). IGF‐1, IGFBP‐3 and sex hormones were also evaluated. BMD was measured by dual‐energy X‐ray absorptiometry at various bone sites.Results  Plasma leptin increased throughout pubertal growth and the values measured in Tanner stages IV–V were significantly higher than in stages I–II. Gains in BMD were measured throughout puberty at all bone sites, particularly between Tanner stages II and IV. In simple correlation analysis, BMD at all bone sites was positively correlated with plasma leptin, age, bone age, BMI, oestrogen, testosterone, IGF‐1 and IGFBP‐3. However, multivariate analysis using a linear regression model by block (including bone age, anthropometric data and biological parameters) was then performed to determine the factors independently associated with each BMD site, and only bone age, fat‐free soft tissue and BMI remained independent predictors.Conclusion  In FRG characterized by high training volume and low fat mass, plasma leptin levels increased throughout puberty and were partially related to body composition changes. Despite the simultaneous increases in plasma leptin and BMD during pubertal growth, it was not possible to differentiate the leptin impact on bone independently from anthropometric parameters.
Effects of omnivorous filter‐feeding fish and nutrient enrichment on the plankton community and water transparency of a tropical reservoir
Authors: MENEZES ROSEMBERG FERNANDES , ATTAYDE JOSÉ LUIZ , RIVERA VASCONCELOS FRANCISCO 
Published: September 2009

Summary1. The major aim of this study was to test the hypothesis that nutrient enrichment and the introduction of the Nile tilapia (Oreochromis niloticus), an exotic omnivorous filter‐feeding fish, operate interdependently to regulate plankton communities and water transparency of a tropical reservoir in the semi‐arid northeastern Brazil.2. A field experiment was performed for 5 weeks in 20 enclosures (9.8 m3) to which four treatments were randomly allocated: tilapia addition (F), nutrient addition (N), tilapia and nutrient addition (F + N) and a control treatment with no tilapia or nutrient addition (C). A two‐way repeated measures anova was undertaken to test for time, tilapia and nutrient effects and their interactions on water transparency, total phosphorus and total nitrogen concentrations, phytoplankton biovolume and zooplankton biomass.3. Nutrient addition had no effect except on rotifer biomass, but there were significant fish effects on the biomass of total zooplankton, copepod nauplii, rotifers, cladocerans and calanoid copepods and on the biovolume of total phytoplankton, large algae (GALD ≥ 50 μm), Bacillariophyta and Zygnemaphyceae and on Secchi depth. In addition, we found significant interaction effects between tilapia and nutrients on Secchi depth and rotifers. Overall, tilapia decreased the biomass of most zooplankton taxa and large algae (diatoms) and decreased water transparency, while nutrient enrichment increased the biomass of rotifers, but only in the absence of tilapia.4. In conclusion, the influence of fish on the reservoir plankton community and water transparency was significant and even greater than that of nutrient loading. This suggests that biomanipulation of filter‐feeding tilapias may be of importance for water quality management of eutrophic reservoirs in tropical semi‐arid regions.
Giving‐up densities and ideal pre‐emptive patch use in a predatory benthic stream fish
Authors: PETTY J. TODD , GROSSMAN GARY D. 
Published: September 2009

Summary1. We used observational and experimental field studies together with an individual‐based simulation model to demonstrate that behaviours of mottled sculpin (Cottus bairdi) were broadly consistent with the expectations of Giving‐Up Density theory and an Ideal Pre‐emptive Distribution habitat selection model.2. Specifically we found that: (i) adult mottled sculpin established territories within patches characterised by significantly higher prey densities and prey renewal rates than patches occupied by juveniles or randomly selected patches; (ii) patches abandoned by adult sculpin possessed significantly lower prey densities than newly occupied patches, although this was not true for juveniles; (iii) the observed giving‐up density (GUD) for adult sculpin (i.e. average prey density in patches recently abandoned) increased linearly with increasing fish size up to the average prey density measured in randomly selected patches (i.e. 350 prey items per 0.1 m2) and decreased with increasing sculpin density and (iv) juveniles rapidly shifted their distribution towards the highest quality patches following removal of competitively dominant adult sculpin.3. These results provide the first evidence of the applicability of GUD theory to a stream‐dwelling organism, and they elucidate the underlying factors influencing juvenile and adult sculpin habitat selection and movement behaviours. Furthermore, optimal patch use, ideal pre‐emptive habitat selection and juvenile ‘floating’ provide behavioural mechanisms linking environmental heterogeneity in the stream benthos to density‐dependent regulation of mottled sculpin populations in this system.
DIP/WISH‐deficient mice reveal Dia‐ and N‐WASP‐interacting protein as a regulator of cytoskeletal dynamics in embryonic fibroblasts
Authors: Fukumi‐Tominaga Tomoko , Mori Yoshiko , Matsuura Atsuko , Kaneko Keiko , Matsui Makoto , Ogata Masato , Tominaga Makoto 
Published: September 2009

DIP/WISH binds to mammalian diaphanous and N‐WASP, and functions as a scaffold protein by binding to Nck protein (called SPIN90). In addition, DIP/WISH accelerates actin polymerization through integration with N‐WASP and is involved in cytoskeletal dynamics. We previously reported that DIP controls the activities of Rho GTPases in a Src‐dependent manner, and accordingly contributes to cell motility (Meng et al. 2004). Here, we made the mice lacking DIP/WISH and demonstrated that DIP/WISH is critical for cell motility and adhesion by using murine embryonic fibroblasts (MEF). Rho activity was higher in DIP/WISH‐deficient MEF cells even before platelet‐derived growth factor (PDGF) or adhesion stimulation. Cell motility and adhesion were impaired in DIP/WISH‐deficient MEF cells, and the MEF cells moved little probably due to the deficiency of tail retractions although they had many small membrane ruffles. Consistent with high Rho activity, DIP/WISH‐deficient MEF cells exhibited many stress fibers due to clustering pre‐existing actin filament. Thus, DIP/WISH is a negative regulator of Rho and modulates cell adhesion by controlling the integration of adhesion molecules.
Do elevated atmospheric CO2and O3affect food quality and performance of folivorous insects on silver birch?
Authors: PELTONEN PETRI A. , VAPAAVUORI ELINA , HEINONEN JAAKKO , JULKUNEN‐TIITTO RIITTA , HOLOPAINEN JARMO K. 
Published: September 2009

AbstractThe individual and combined effects of elevated CO2and O3on the foliar chemistry of silver birch (Betula pendulaRoth) and on the performance of five potential birch‐defoliating insect herbivore species (two geometrid moths, one lymantrid moth and two weevils) were examined. Elevated CO2decreased the water concentration in both short‐ and long‐shoot leaves, but the effect of CO2on the concentration of nitrogen and individual phenolic compounds was mediated by O3treatment, tree genotype and leaf type. Elevated O3increased the total carbon concentration only in short‐shoot leaves. Bioassays showed that elevated CO2increased the food consumption rate of juvenileEpirrita autumnataandRheumaptera hastatalarvae fed with short‐ and long‐shoot leaves in spring and mid‐summer, respectively, but had no effect on the growth of larvae. The contribution of leaf quality variables to the observed CO2effects indicate that insect compensatory consumption may be related to leaf age. Elevated CO2increased the food preference of only two tested species:Phyllobius argentatus(CO2alone) andR. hastata(CO2combined with O3). The observed stimulus was dependent on tree genotype and the measured leaf quality variables explained only a portion of the stimulus. Elevated O3decreased the growth of flush‐feeding youngE. autumnatalarvae, irrespective of CO2concentration, apparently via reductions in general food quality. Therefore, the increasing tropospheric O3concentration could pose a health risk for juvenile early‐season birch folivores in future. In conclusion, the effects of elevated O3were found to be detrimental to the performance of early‐season insect herbivores in birch whereas elevated CO2had only minor effects on insect performance despite changes in food quality related foliar chemistry.
Lipoprotein lipase and endothelial lipase in human testis and in germ cell neoplasms
Authors: Nielsen J. E. , Lindegaard M. L. , Friis‐Hansen L. , Almstrup K. , Leffers H. , Nielsen L. B. , Rajpert‐De Meyts E. 
Published: September 2009

SummaryThe aim of this study was to investigate endothelial lipase (EL, LIPG) and lipoprotein lipase (LPL) mRNA and protein expression in normal human testis and testicular germ cell tumours (GCT). Both EL and LPL were expressed in normal seminiferous tubules and in the interstitial compartment. EL mRNA and protein were found in all germ cells as well as in Sertoli and Leydig cells. EL mRNA was abundant in pre‐invasive carcinoma in situ (CIS) cells and GCTs, and EL protein was present in the cytoplasm of these cells. LPL mRNA was also relatively abundant in germ cells, Sertoli cells, CIS cells and GCTs. The LPL protein, however, was restricted to the cell membranes of pachytene spermatocytes and spermatids in normal tubules, absent from CIS cells and scarcely represented in tumours. The distribution of LPL protein in non‐seminomas resembled the distribution of OCT3/4, a marker of embryonal carcinoma. The results suggest that both EL and LPL participate in the supply of nutrients and steroidogenesis in the testes, and that especially EL may be important for the supply of cholesterol for testosterone production in the Leydig cells. The partial cellular separation of the expression of the two lipases in normal testis suggests the existence of distinct biological roles, perhaps developmentally regulated, as indicated by the LPL expression in GCTs with embryonic features. A high expression of EL and abundance of lipid in tubules with CIS may have a diagnostic value.
Molecular characterization of staphyloferrin B biosynthesis in Staphylococcus aureus
Authors: Cheung Johnson , Beasley Federico C. , Liu Suya , Lajoie Gilles A. , Heinrichs David E. 
Published: September 2009

SummarySiderophores are iron‐scavenging molecules produced by many microbes. In general, they are synthesized using either non‐ribosomal peptide synthetase (NRPS) or NRPS‐independent siderophore (NIS) pathways. Staphylococcus aureus produces siderophores, of which the structures of staphyloferrin A and staphyloferrin B are known. Recently, the NIS biosynthetic pathway for staphyloferrin A was characterized. Here we show that, in S. aureus, the previously identified sbn (siderophore biosynthesis) locus encodes enzymes required for the synthesis of staphyloferrin B, an α‐hydroxycarboxylate siderophore comprised of l‐2,3‐diaminopropionic acid, citric acid, 1,2‐diaminoethane and α‐ketoglutaric acid. Staphyloferrin B NIS biosynthesis was recapitulated in vitro, using purified recombinant Sbn enzymes and the component substrates. In vitro synthesized staphyloferrin B readily promoted the growth of iron‐starved S. aureus, via the ABC transporter SirABC. The SbnCEF synthetases and a decarboxylase, SbnH, were necessary and sufficient to produce staphyloferrin B in reactions containing component substrates l‐2,3‐diaminopropionic acid, citric acid and α‐ketoglutaric acid. Since 1,2‐diaminoethane was not required, this component of the siderophore arises from the SbnH‐dependent decarboxylation of a 2,3‐diaminoproprionic acid‐containing intermediate. Liquid chromatography‐electrospray ionization‐mass spectrometry (LC‐ESI‐MS) analyses of a series of enzyme reactions identified mass ions corresponding to biosynthetic intermediates, allowing for the first proposed biosynthetic pathway for staphyloferrin B.
Cannibalism enhances biofilm development in Bacillus subtilis
Authors: López Daniel , Vlamakis Hera , Losick Richard , Kolter Roberto 
Published: September 2009

SummaryCannibalism is a mechanism to delay sporulation in Bacillus subtilis. Cannibal cells express the skf and sdp toxin systems to lyse a fraction of their sensitive siblings. The lysed cells release nutrients that serve to feed the community, effectively delaying spore formation. Here we provide evidence that the subpopulation of cells that differentiates into cannibals is the same subpopulation that produces the extracellular matrix that holds cells together in biofilms. Cannibalism and matrix formation are both triggered in response to the signalling molecule surfactin. Nutrients released by the cannibalized cells are preferentially used by matrix‐producing cells, as they are the only cells expressing resistance to the Skf and Sdp toxins. As a result this subpopulation increases in number and matrix production is enhanced when cannibalism toxins are produced. The cannibal/matrix‐producing subpopulation is also generated in response to antimicrobials produced by other microorganisms and may thus constitute a defense mechanism to protect B. subtilis from the action of antibiotics in natural settings.
Mining for robust transcriptional and metabolic responses to long‐term salt stress: a case study on the model legume Lotus japonicus
Authors: SANCHEZ DIEGO H. , SZYMANSKI JEDRZEJ , ERBAN ALEXANDER , UDVARDI MICHAEL K. , KOPKA JOACHIM 
Published: September 2009

ABSTRACTTranslational genomics, the use of model species to generate knowledge about biological processes and the functions of genes, offers great promise to biotechnologists. Few studies have sought robust responses of model plants to environmental stresses, such as salinity, by altering the stress dosage or by repeating experiments in consecutive years and/or different seasons. We mined our published and unpublished data on legume salt acclimation for robust system features at the ionomic, transcriptomic and metabolomic levels. We analysed data from the model legume Lotus japonicus, obtained through six independent, long‐term, non‐lethal salt stress experiments which were carried out over two consecutive years. Best possible controlled greenhouse conditions were applied and two main questions asked: how reproducible are results obtained from physiologically meaningful salinity experiments, and what degree of bias may be expected if conclusions are drawn from less well‐repeated sampling? A surprisingly large fraction of the transcriptional and metabolic responses to salt stress were not reproducible between experiments. A core set of robust changes was found that was shared between experiments. Many of these robust responses were qualitatively and quantitatively conserved between different accessions of the same species, indicating that the robust responses may be a sound starting point for translational genomics.
Oxidative mechanisms in schizophrenia and their relationship with illness subtype and symptom profile
Authors: Pazvantoglu Ozan , Selek Sahabettin , Okay I. Tuncer , Sengul Cem , Karabekiroglu Koray , Dilbaz Nesrin , Erel Özcan 
Published: September 2009

Aim:  The aim of the present study was to investigate the differences in the antioxidant–oxidant balance (AO‐OB) between schizophrenic patients and healthy individuals and to explore the relationship of AO‐OB with illness subtypes and symptom profiles.Methods:  After a 15‐day drug‐free period, schizophrenia patients (n = 50) in a clinical sample, and age‐ and sex‐matched healthy subjects (n = 49) were enrolled. Total antioxidant potentials (TAOP) and total peroxide levels (TPEROX) of all participants were measured and the oxidative stress index (OSI) was calculated. The assessment included structured measurements, including the Positive and Negative Syndrome Scale (PANSS), and the Brief Psychiatric Rating Scale (BPRS).Results:  TAOP had a significant positive correlation with age at onset of schizophrenia (P = 0.013), a negative correlation with the PANSS negative subscale scores (P = 0.008), a negative correlation with the PANSS total scores (P < 0.001), and a significant negative correlation with BPRS scores (P = 0.001). OSI had a significant negative correlation with age at onset (P = 0.046) and a significant positive correlation with PANSS negative subscale (P = 0.015). A multiple regression model indicated a significant linear combination of age, gender, duration of illness, subtype of schizophrenia, and PANSS scores, in which only the subtype of schizophrenia made a statistically significant contribution to predicting mean OSI (F[5,35] = 2.44, P = 0.04).Conclusion:  Several parameters in the pathogenesis of schizophrenia, such as age of onset, level of negative symptoms, and subtype of illness, but not the presence of the illness itself, are associated with the level of oxidative stress.
Some observations on the strength and fatigue properties of samples extracted from cast iron water mains
Authors: BELMONTE H. M. S. , MULHERON M. J. , SMITH P. A. 
Published: September 2009

ABSTRACTThe strength and fatigue properties of cast iron samples taken from water distribution mains have been investigated. Specimens were sourced from three sections of pipe which had experienced varying amounts of corrosion in service, enabling the variable of pipe condition to be incorporated within the study.The strengths in four‐point flexure of small specimens from the pipes examined were described using Weibull statistics; different characteristic strengths and Weibull moduli were obtained, according to the pipe condition. A further set of samples from each pipe were subjected to flexural fatigue at a range of stress levels (different stress levels were chosen for each pipe based on the short‐term strength properties) and residual strength tests were carried out on the surviving samples from one stress level for each pipe. There is evidence of a fatigue effect for all sample sets. There were slight differences in the residual strength behaviour – the residual strength of the survivors was reduced in the samples from the section in best condition while the residual strength of the survivors from the other two pipe sections was relatively unaffected. These trends are discussed with reference to condition and fatigue stress level.The results suggest that mechanical fatigue may be a factor in the failure of water distribution pipes. The results may have implications for large diameter trunk mains as well as the small diameter water distribution pipes tested here. To assess the effect in more detail, consideration needs to be given to scaling effects in fatigue and the likely levels of any fatigue stress seen in service.