bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phylogeography of a species complex of lowland Neotropical rain forest trees (Carapa, Meliaceae)
Authors: Scotti‐Saintagne Caroline , Dick Christopher W. , Caron Henri , Vendramin Giovanni G. , Guichoux Erwan , Buonamici Anna , Duret Caroline , Sire Pierre , Valencia Renato , Lemes Maristerra R. , Gribel Rogério , Scotti Ivan 
Published: February 2012

AbstractAim  Many tropical tree species have poorly delimited taxonomic boundaries and contain undescribed or cryptic species. We examined the genetic structure of a species complex in the tree genus Carapa in the Neotropics in order to evaluate age, geographic patterns of diversity and evolutionary relationships, and to quantify levels of introgression among currently recognized species.Location  Lowland moist forests in the Guiana Shield, the Central and Western Amazon Basin, Chocó and Central America.Methods  Genetic structure was analysed using seven nuclear simple sequence repeats (nuSSR), five chloroplast SSRs (cpSSR), and two chloroplast DNA (cpDNA) intergenic sequences (trnH–psbA and trnC–ycf6). Bayesian clustering analysis of the SSR data was used to infer population genetic structure and to assign 324 samples to their most likely genetic cluster. Bayesian coalescence analyses were performed on the two cpDNA markers to estimate evolutionary relationships and divergence times.Results  Two genetic clusters (nu_guianensis and nu_surinamensis) were detected, which correspond to the Neotropical species C. guianensis (sensu latu) and C. surinamensis. Fourteen cpDNA haplotypes clustered into six haplogroups distributed between the two nuclear genetic clusters. Divergence between the haplogroups was initiated in the Miocene, with some haplotype structure evolving as recently as the Pleistocene. The absence of complete lineage sorting between the nuclear and chloroplast genomes and the presence of hybrid individuals suggest that interspecific reproductive barriers are incomplete. NuSSR diversity was highest in C. guianensis and, within C. guianensis, cpDNA diversity was highest in the Central and Western Amazon Basin. Regional genetic differentiation was strong but did not conform to an isolation‐by‐distance process or exhibit a phylogeographical signal.Main conclusions  The biogeographical history of Neotropical Carapa appears to have been influenced by events that took place during the Neogene. Our results point to an Amazonian centre of origin and diversification of Neotropical Carapa, with subsequent migration to the Pacific coast of South America and Central America. Gene flow apparently occurs among species, and introgression events are supported by inconsistencies between chloroplast and nuclear lineage sorting. The absence of phylogeographical structure may be a result of the ineffectiveness of geographical barriers among populations and of reproductive isolation mechanisms among incipient and cryptic species in this species complex.
Hsp33 confers bleach resistance by protecting elongation factor Tu against oxidative degradation in Vibrio cholerae
Authors: Wholey Wei‐Yun , Jakob Ursula 
Published: February 2012

SummaryThe redox‐regulated chaperone Hsp33 protects bacteria specifically against stress conditions that cause oxidative protein unfolding, such as treatment with bleach or exposure to peroxide at elevated temperatures. To gain insight into the mechanism by which expression of Hsp33 confers resistance to oxidative protein unfolding conditions, we made use of Vibrio cholerae strain O395 lacking the Hsp33 gene hslO. We found that this strain, which is exquisitely bleach‐sensitive, displays a temperature‐sensitive (ts) phenotype during aerobic growth, implying that V. cholerae suffers from oxidative heat stress when cultivated at 43°C. We utilized this phenotype to select for Escherichia coli genes that rescue the ts phenotype of V. cholerae ΔhslO when overexpressed. We discovered that expression of a single protein, the elongation factor EF‐Tu, was sufficient to rescue both the ts and bleach‐sensitive phenotypes of V. cholerae ΔhslO. In vivo studies revealed that V. cholerae EF‐Tu is highly sensitive to oxidative protein degradation in the absence of Hsp33, indicating that EF‐Tu is a vital chaperone substrate of Hsp33 in V. cholerae. These results suggest an ‘essential client protein’ model for Hsp33's chaperone action in Vibrio in which stabilization of a single oxidative stress‐sensitive protein is sufficient to enhance the oxidative stress resistance of the whole organism.
Aerial development in Streptomyces coelicolor requires sortase activity
Authors: Duong Andrew , Capstick David S. , Di Berardo Christina , Findlay Kim C. , Hesketh Andrew , Hong Hee‐Jeon , Elliot Marie A. 
Published: February 2012

SummaryStreptomyces coelicolor is a multicellular bacterium whose life cycle encompasses three differentiated states: vegetative hyphae, aerial hyphae and spores. Among the factors required for aerial development are the ‘chaplins’, a family of eight secreted proteins that coat the surface of aerial hyphae. Three chaplins (the ‘long’ chaplins, ChpA, B and C) possess an LAXTG‐containing C‐terminal sorting signal and are predicted sortase substrates. The five remaining ‘short’ chaplins are presumed to be associated with the cell surface through interactions with the long chaplins. We show here that two sortase enzymes, SrtE1 and SrtE2, cleave LAXTG‐containing peptides at two distinct positions in vitro, and are required for cell wall anchoring of ChpC in vivo. srtE1/E2 double mutants are delayed in aerial hyphae formation, do not sporulate and fail to display all short chaplins on their aerial surfaces. Surprisingly, these mutant characteristics were not shared by a long chaplin mutant, which exhibited only modest delays in aerial development, leading us to revise the current model of chaplin‐mediated aerial development. The sortase mutant phenotype, instead, appears to stem from an inability to transcribe aerial hyphae‐specific genes, whose products have diverse functions. This suggests that sortase activity triggers an important, and previously unknown, developmental checkpoint.
Expression of the RNA recognition motif protein RBP10 promotes a bloodstream‐form transcript pattern in Trypanosoma brucei
Authors: Wurst Martin , Seliger Beate , Jha Bhaskar Anand , Klein Cornelia , Queiroz Rafael , Clayton Christine 
Published: February 2012

SummaryWhen Trypanosoma brucei differentiates from the bloodstream form to the procyclic form, there are decreases in the levels of many mRNAs encoding proteins required for the glycolytic pathway, and the mRNA encoding the RNA recognition motif protein RBP10 decreases in parallel. We show that RBP10 is a cytoplasmic protein that is specific to bloodstream‐form trypanosomes, where it is essential. Depletion of RBP10 caused decreases in many bloodstream‐form‐specific mRNAs, with increases in mRNAs associated with the early stages of differentiation. The changes were similar to, but more extensive than, those caused by glucose deprivation. Conversely, forced RBP10 expression in procyclics induced a switch towards bloodstream‐form mRNA expression patterns, with concomitant growth inhibition. Forced expression of RBP10 prevented differentiation of bloodstream forms in response to cis‐aconitate, but did not prevent expression of key differentiation markers in response to glucose deprivation. RBP10 was not associated with heavy polysomes, showed no detectable in vivo binding to RNA, and was not stably associated with other proteins. Tethering of RBP10 to a reporter mRNA inhibited translation, and halved the abundance of the bound mRNA. We suggest that RBP10 may prevent the expression of regulatory proteins that are specific to the procyclic form.
Ligand and antagonist driven regulation of the Vibrio cholerae quorum‐sensing receptor CqsS
Authors: Wei Yunzhou , Ng Wai‐Leung , Cong Jianping , Bassler Bonnie L. 
Published: February 2012

SummaryQuorum sensing, a bacterial cell–cell communication process, controls biofilm formation and virulence factor production in Vibrio cholerae, a human pathogen that causes the disease cholera. The major V. cholerae autoinducer is (S)‐3‐hydroxytridecan‐4‐one (CAI‐1). A membrane bound two‐component sensor histidine kinase called CqsS detects CAI‐1, and the CqsS → LuxU → LuxO phosphorelay cascade transduces the information encoded in CAI‐1 into the cell. Because the CAI‐1 ligand is known and because the signalling circuit is simple, consisting of only three proteins, this system is ideal for analysing ligand regulation of a sensor histidine kinase. Here we reconstitute the CqsS → LuxU → LuxO phosphorylation cascade in vitro. We find that CAI‐1 inhibits the initial auto‐phosphorylation of CqsS whereas subsequent phosphotransfer steps and CqsS phosphatase activity are not CAI‐1‐controlled. CAI‐1 binding to CqsS causes a conformational change that renders His194 in CqsS inaccessible to the CqsS catalytic domain. CqsS mutants with altered ligand detection specificities are faithfully controlled by their corresponding modified ligands in vitro. Likewise, pairing of agonists and antagonists allows in vitro assessment of their opposing activities. Our data are consistent with a two‐state model for ligand control of histidine kinases.
Role of Lactobacillus acidophilus loaded floating beads in chronic fatigue syndrome: behavioral and biochemical evidences
Authors: Singh P. K. , Chopra K. , Kuhad A. , Kaur I. P. 
Published: February 2012

AbstractBackground  In recent years the interface between neuropsychiatry and gastroenterology has converged in to a new discipline referred to as enteric neuroscience. Implications of brain–gut communication in the pathogenesis of psychiatric disorders indicate a possible role of suitably packaged/delivered probiotics as newer therapeutic options. In the present study probable role of per‐oral administration of free Lactobacillus acidophilus (LAB) and LAB loaded alginate beads in attenuation of the symptoms associated with chronic fatigue syndrome (CFS) were evaluated.Methods  Chronic fatigue syndrome following physical fatigue was induced in rats by forcing them to swim (forced swim test; FST) in water till exhaustion, after weighing them down with 10% their body weight, daily for 28 days. Immobility (I) and postswim fatigue time (PSF) were taken as suitable markers. Free LAB and LAB loaded floating beads (FBs) were administered, from 21 to 28 days.Key Results  Immobility and PSF were found to increase considerably in FST rats (665 ± 22 s and 196 ± 6 s) as compared with the naïve (32 ± 7 s and 22 ± 2 s) at 20 days, establishing severe fatigue like behavior. FST control group exhibited significant (P < 0.05) hypertrophy of spleen, hypotrophy of thymus, and increased oxido‐nitrosative stress in brain and tumor necrosis factor‐α (TNF‐α) levels in serum. Treatment with LAB and LAB FBs significantly decreased I and PSF and attenuated (P < 0.05) oxido‐nitrosative stress and TNF‐α levels. Spleen and thymus were also restored to their original size in this group.Conclusions & Inferences  The findings suggest a valuable therapeutic role of LAB especially when incorporated into alginate beads for the treatment of CFS.
Assessing the impact of deliberative processes on the views of participants: is it ‘in one ear and out the other’?
Authors: Stafinski Tania , Menon Devidas , Yasui Yutaka 
Published: February 2012

AbstractBackground  Interest in citizens’ juries for eliciting the views of the public to inform coverage decisions on new health technologies has grown. However, evaluative information, particularly regarding their short‐ and/or longer‐term impact on participants’ views is limited. As citizens’ juries can be resource intensive, such information is required to make ‘evidence‐based’ decisions about their use.Objectives  To assess the impact of citizens’ juries on participants’ preferences for the distribution of health care across populations over time.Setting and participants  Two citizens’ juries, involving a different representative sample of the public, were held. Participants completed identical questionnaires before (T1), directly after (T2) and 6 weeks following the jury (T3). Questionnaires comprised rating, ranking and choice‐based questions related to four characteristics of competing patient populations (age, current health, life expectancy without treatment and health gain resulting from an intervention). Semi‐structured telephone interviews were also conducted to explore the impact of the jury on participants’ distributive preferences. Changes in responses to the self‐administered survey over the three time points were assessed quantitatively, while interview questions were analysed using qualitative techniques.Results  No significant differences in responses to rating questions were observed. Pre/post‐jury changes in the rankings of two factors were statistically significant in one of the juries. However, in both juries, T1–T2 changes in responses to several of the choice‐based questions reached statistical significance. The number was lower between T2 and T3, suggesting that jurors retained their views. According to findings from the interviews, jurors’ views changed or were clarified through participation in the jury.Conclusions  There appears to be evidence suggesting that the views of individuals who participate in citizens’ juries change as a result of the experience, and those ‘informed’ views are sustained.
Hsp70 protein levels and thermotolerance in Drosophila subobscura: a reassessment of the thermal co‐adaptation hypothesis
Authors: CALABRIA G. , DOLGOVA O. , REGO C. , CASTAÑEDA L. E. , REZENDE E. L. , BALANYÀ J. , PASCUAL M. , SØRENSEN J. G. , LOESCHCKE V. , SANTOS M. 
Published: February 2012

AbstractTheory predicts that geographic variation in traits and genes associated with climatic adaptation may be initially driven by the correlated evolution of thermal preference and thermal sensitivity. This assumes that an organism’s preferred body temperature corresponds with the thermal optimum in which performance is maximized; hence, shifts in thermal preferences affect the subsequent evolution of thermal‐related traits. Drosophila subobscura evolved worldwide latitudinal clines in several traits including chromosome inversion frequencies, with some polymorphic inversions being apparently associated with thermal preference and thermal tolerance. Here we show that flies carrying the warm‐climate chromosome arrangement O3+4 have higher basal protein levels of Hsp70 than their cold‐climate Ost counterparts, but this difference disappears after heat hardening. O3+4 carriers are also more heat tolerant, although it is difficult to conclude from our results that this is causally linked to their higher basal levels of Hsp70. The observed patterns are consistent with the thermal co‐adaptation hypothesis and suggest that the interplay between behaviour and physiology underlies latitudinal and seasonal shifts in inversion frequencies.
Embryonic and Fetal Development in – Pigmy Rice Rat – Oligoryzomys sp. (Rodentia, Sigmodontinae) and its Significance for Being a new Experimental Model
Authors: Favaron P. O. , Rodrigues M. N. , Oliveira M. F. , Biasi C. M. , Miglino M. A. 
Published: February 2012

SummaryOligoryzomys (Cricetidae, Sigmodontinae) is a common rodent genus from South America that includes a couple of very similar species. Related species have been used as experimental model for understanding several diseases for which these species are reservoirs. In order to provide a better understanding of the embryological aspects of this group, herein we showed data on the embryonic and fetal development in Oligoryzomys sp. Eight specimens of different stages of gestation were obtained from the Collection of the Zoology Museum of University of Sao Paulo, Brazil. Gestational ages were estimated by crown‐rump‐length according to Evans and Sack (1973). To address our analysis after examining the gross morphology, tissues from several organs were processed for light and scanning electron microscopy. Morphological data on the systems (nervous system, cardiorespiratory system, intestinal tract and urogenital system) were described in detail. Finally, the findings were compared with what is known about embryological aspects in other rodent species in order to establish similarities and differences during the organogenesis in different species.
Right hemispheric dominance and interhemispheric cooperation in gaze‐triggered reflexive shift of attention
Authors: Okada Takashi , Sato Wataru , Kubota Yasutaka , Toichi Motomi , Murai Toshiya 
Published: February 2012

Aims:  The neural substrate for the processing of gaze remains unknown. The aim of the present study was to clarify which hemisphere dominantly processes and whether bilateral hemispheres cooperate with each other in gaze‐triggered reflexive shift of attention.Methods:  Twenty‐eight normal subjects were tested. The non‐predictive gaze cues were presented either in unilateral or bilateral visual fields. The subjects localized the target as soon as possible.Results:  Reaction times (RT) were shorter when gaze‐cues were congruent toward than away from targets, whichever visual field they were presented in. RT were shorter in left than right visual field presentations. RT in mono‐directional bilateral presentations were shorter than both of those in left and right presentations. When bi‐directional bilateral cues were presented, RT were faster when valid cues were presented in the left than right visual fields.Conclusion:  The right hemisphere appears to be dominant, and there is interhemispheric cooperation in gaze‐triggered reflexive shift of attention.
Identification and molecular phylogenetics of the cryptic species of the Gonipterus scutellatus complex (Coleoptera: Curculionidae: Gonipterini)
Authors: Mapondera Tendai S , Burgess Treena , Matsuki Mamoru , Oberprieler Rolf G 
Published: February 2012

AbstractThe Eucalyptus Weevil, generally referred to as Gonipterus scutellatus Gyllenhal, 1833 is a significant pest of Eucalyptus species in Africa, America, Europe and New Zealand. It has recently become a pest of Eucalyptus globulus plantations in Western Australia, despite the presence there of the mymarid egg‐parasitoid Anaphes nitens (Girault). Recent taxonomic study has indicated G. scutellatus to comprise a complex of cryptic species, obscuring the identity of the various pest populations of the weevil in the world. We examined (1) whether the apparent cryptic species identifiable on genital differences have a genetic basis; (2) the distribution of these species; and (3) the origin of the population in Western Australia. We studied specimens from across the distribution range of Eucalyptus Weevil in Australia and obtained sequences of three genes from them: cytochrome oxidase I mtDNA, elongation‐factor 1‐α nuclear DNA and 18s rDNA. The cladogram of COI haplotypes resolved 10 well supported clades fully corresponding with genital‐morphologically distinct species, eight of them constituting a monophyletic G. scutellatus complex. Only four of these species proved to be described, as G. balteatusLea, 1897G. platensis (Marelli, 1926), G. pulverulentusLea, 1897 and G. scutellatus Gyllenhal, 1833. The pest species in the world were found to be G. platensis (New Zealand, America, western Europe), G. pulverulentus (eastern South America) and an undescribed species (Africa, France, Italy). The population of G. platensis in Western Australia showed little genetic variation and is indicated to be a recent introduction from Tasmania. The discrimination of the cryptic species of the G. scutellatus complex enables improvements in the management of the pest species in terms of biological control and plantation practices. Our study highlights the critical importance of proper taxonomic studies underpinning biocontrol programs.
Neonates presenting with temperature symptoms: Role in the diagnosis of early onset sepsis
Authors: Hofer Nora , Müller Wilhelm , Resch Bernhard 
Published: February 2012

AbstractBackground:  In this study, we aimed to evaluate the role of fever, hypothermia, and temperature instability in term and preterm newborns during the first 3 days of life and to identify risk factors for early onset sepsis (EOS) among newborns presenting with these temperature symptoms.Methods:  In this retrospective cohort study set in our level III neonatal intensive care unit, we included all newborns hospitalized within the first 24 h of life from 2004 to 2007.Results:  Of 851 newborns, 127 presented with temperature symptoms during the first 3 days of life (15%): 69 had fever, 69 had hypothermia, and 55 had temperature instability (8%, 8%, and 6%, respectively). Of 127 newborns presenting with temperature symptoms, 14 had culture‐proven EOS/pneumonia (33% of all 42 newborns with culture‐proven EOS/pneumonia), 67 had clinical EOS (30% of all 209 newborns with clinical EOS) and 46 were EOS‐negative (8% of all 600 EOS‐negatives). Factors associated with culture‐proven EOS/pneumonia in newborns presenting with temperature symptoms were maternal fever (P= 0.009), chorioamnionitis (P < 0.001), antibiotic therapy of the mother (P= 0.04), poor skin color (P= 0.001) and syndrome of persistent fetal circulation (P= 0.01).Conclusions:  Every seventh newborn hospitalized at our neonatal intensive care unit developed fever, hypothermia and/or temperature instability during the first 3 days of life. Two‐thirds of them had culture‐proven or clinical sepsis. Temperature symptoms were rarely observed in EOS‐negative newborns (8%) but despite low sensitivity, were highly specific for bacterial infection in preterm and term newborns.
Pilot randomized trial of a nanopulse retinal laser versus conventional photocoagulation for the treatment of diabetic macular oedema
Authors: Casson Robert J , Raymond Grant , Newland Henry S , Gilhotra Jagjit S , Gray Tim L 
Published: February 2012

AbstractBackground:  To assess the efficacy of a new nanopulse laser, retinal regeneration therapy for the treatment of diabetic macular oedema.Design:  Randomized, non‐inferiority, trial.Participants:  20 eyes of 17 subjects in the retinal regeneration therapy group and 18 eyes of 14 subjects in the conventional group were analysed.Methods:  The treatment group received retinal regeneration therapy laser, and the control group received photocoagulation.Main Outcome Measures:  The primary outcome was the optical coherence tomography‐measured change in central retinal thickness at 6 months. A secondary outcome was the change in logarithm of minimum angle of resolution visual acuity at 6 months. Non‐inferiority required the one‐sided 95% confidence interval of the mean retinal thickness reduction after retinal regeneration therapy to be within 35 µm of the reduction after control laser.Results:  When outliers were included in the dataset, the difference in retinal thickness reduction by analysis of covariance was 10.9 (standard deviation 17.6) mm in favour of the control laser. The difference between groups in retinal thickness reduction was 40.8 mm. If two extreme outliers were excluded, the difference was 5.6 (standard deviation 14.2) mm in favour of the retinal regeneration therapy laser, and the D optical coherence tomography was 18.5 mm. The visual acuity difference between groups was 0.059, meeting non‐inferiority requirements.Conclusions:  Although retinal thickness reduction was not unambiguously non‐inferior, in the short‐term, retinal regeneration therapy approximates the clinical efficacy of conventional photocoagulation, stabilizing visual acuity and providing motivation for larger trials assessing retinal regeneration therapy.